179 results about "Triangular grid" patented technology

The invention relates to a low-altitude flight dynamic safety guarantee method and system based on airspace gridding, and relates to the technical field of low-altitude airspace management, and the method comprises the steps: constructing a gridding airspace; on the basis of the gridding airspace, labeling network attributes for each grid unit in real time and evaluating a low-altitude safety state; according to network attributes, extracting a grid center point of an airspace grid which is evaluated to be in a low-risk range as a safe flight point, and dividing the gridding airspace into a plurality of safe triangular grids; and according to the predicted trajectory of the aircraft, selecting a candidate point with the lowest risk cost from adjacent triangles of the safety triangular mesh, and introducing a risk cost function to dynamically adjust the distribution of flight path points. According to the invention, the flight path of the aircraft group can be dynamically adjusted according to the environment change, and the stability and safety of cluster task execution are improved.

The invention discloses a shield tunneling machine driving attitude adjusting method and system under multi-sensor monitoring, and relates to the technical field of shield tunneling machine control. Interactive engineering planning is carried out, a tunnel center line is identified, a driving reference axis is determined, a tunnel section is subjected to triangular grid division, and an attitude adjusting module is trained by setting the attitude position relation of a shield tunneling machine; and collecting measurement data, carrying out shield attitude misalignment measurement and adjustment decision of each shield single ring in the tunneling operation of the shield tunneling machine, determining an attitude adjustment strategy, and responding to a control center of the shield tunneling machine to carry out tunneling attitude adjustment management and control. The method and the device are used for solving the technical problems that in the prior art, decision consideration is not comprehensive enough, the technical support degree is insufficient, instantaneity and adaptivity of tunneling posture adjustment cannot be guaranteed, and consequently accuracy and reliability of an adjustment strategy are insufficient. High-precision real-time adjustment and control of the posture of the shield tunneling machine are achieved, and construction safety and efficiency are effectively improved.

The invention relates to the technical field of MOS (metal oxide semiconductor), and discloses a VDMOSFET (vertical double-diffused metal oxide semiconductor field effect transistor) device with low threshold voltage, which comprises a drain electrode, a semiconductor epitaxial layer, a source electrode, a grid electrode and a grid oxide layer covering the surface of the grid electrode, and is characterized in that an N substrate layer, an N drift layer, an N well layer, a P well layer and a heavily doped P layer are formed in the semiconductor epitaxial layer through ion implantation, the grid electrode comprises a triangular grid electrode and a rectangular grid electrode, the grid oxide layer covering the surface of the triangular grid electrode is in contact with the N substrate layer, and the N drift layer is divided into a left part and a right part by the grid oxide layer. According to the invention, the grid electrode is designed to further comprise the triangular grid electrode, the electric field effect of the grid electrode between the tip part of the triangular grid electrode and the drain electrode is better, but the grid oxide layer wrapped by the triangular grid electrode at the tip part is thicker, so that charges flowing out of the drain electrode gather towards the inside of the heavily doped N layer more quickly along the grid oxide layer; at the moment, more charge flow can be provided in a smaller grid voltage environment.

The invention relates to the technical field of computer-aided manufacturing, and provides a staged processing real-time cutting simulation method and system.The method comprises the steps that S1, initialization modeling is conducted, specifically, a blank voxel grid model, a tool body voxel grid and a triangular grid are built; s2, performing a first simulation stage of low-precision real-time cutting dominated by voxel grids, judging a space overlapping relationship between the tool body voxel grids and the blank voxel grids in real time so as to determine a voxel region to be removed, and deleting blank voxels in the overlapping region through Boolean operation; s3, in the execution process of the first simulation stage, monitoring a preset multi-dimensional switching trigger condition in real time, and when any condition or a combination of multiple conditions is met, entering a second simulation stage; and S4, a second simulation stage of high-precision real-time cutting with the triangular network as the dominant is carried out, the voxel grid intermediate workpiece is converted into a transition triangular grid, and high-precision cutting calculation is carried out based on the triangular grid. And the efficiency-precision contradiction is broken through through a staged strategy.

The invention discloses an image registration method based on improved ORB feature extraction and grid feature matching. The method comprises the following steps: inputting an image to be extracted; using an improved FAST algorithm to extract feature points of the to-be-spliced image; establishing a BRIEF descriptor, and obtaining a BRIEF descriptor with a direction; according to the feature point set of the to-be-spliced image, establishing a Delaunay triangular grid taking the feature points as vertexes; judging the similarity of triangles, and obtaining similar triangles formed by the feature points; matching the similar triangle vertexes by using a Hamming distance to obtain an optimal matching feature point pair; obtaining affine matrix parameters by using an SVD method; according to the image registration method provided by the invention, the image quality is ensured, the feature extraction efficiency and the extraction precision can be improved, wrong matching is reduced, the stability is improved, the real-time performance of video stitching is improved, the waste of memory resources is reduced, the equipment cost is reduced, the working efficiency is greatly improved, and the method is suitable for popularization and application. And a better method is provided for image splicing.

The invention relates to the technical field of MOS semiconductors, and discloses a vertical D-MOSFET with trench isolation and an improved channel structure and a preparation method, the vertical D-MOSFET comprises a plurality of MOS cells which are parallel to one another, each MOS cell comprises a drain electrode, a source electrode, a grid electrode, a grid oxide layer and a semiconductor epitaxial layer, the semiconductor epitaxial layer comprises an N substrate layer, an N diffusion layer, a P + layer, a P well layer and an N well layer, the profile of the cross section of the grid electrode is triangular, and a polycrystalline silicon covering layer is deposited at the junction of the grid electrode and the gate oxide layer; the profile of the cross section of the gate oxide layer is in a semi-elliptical shape, and the profile of the cross section of the polycrystalline silicon covering layer is in a triangular shape. The section profile of the grid electrode is designed to be triangular, the grid oxide layer is controlled to be in a semi-oval shape, electric field distribution and a carrier migration path are optimized, the triangular grid electrode can reduce electric field concentration at the edge of the grid electrode, and the breakdown risk is reduced.

The invention discloses a flood dynamic display method and device, equipment, a medium and a product. The method comprises the steps of performing grid reconstruction on irregular quadrilateral grid data at a plurality of moments based on a triangulated irregular network algorithm, and generating first triangular grid data at the plurality of moments; extracting a target quadrilateral grid from the irregular quadrilateral grid data at multiple moments; determining second triangular mesh data at multiple moments corresponding to the target quadrilateral mesh in the first triangular mesh data at multiple moments; constructing an index structure of the second triangular mesh data based on the index identifier, the first mapping relationship and the second mapping relationship; based on the second triangular mesh data and the index structure, generating a to-be-rendered dynamic water surface data set; and based on a time sequence and a multi-normal superposition rendering technology based on a graphic interface, generating visual data representing dynamic changes of the water surface. In this way, the visualization effect and performance of flood routing simulation are improved.

The invention provides an intelligent photocuring 3D printing model optimization method, and relates to the technical field of photocuring 3D printing, and the method comprises the following steps: obtaining a 3D printing model file uploaded by a user; analyzing geometric information in the model file, and extracting a triangular grid structure, normal vector information and a surface area; key feature areas of curved surfaces, corners and edges in the model are identified, printing parameter data are collected, and a target model summary file is generated; an optimization printing target is defined, an optimization model is generated based on the generative adversarial network, model quality is evaluated through a discriminator network, a multi-target optimization result is analyzed, and an optimal balance point among different targets is found; and testing the optimized model and the printing parameters by using virtual reality, and performing self-adaptive correction according to a simulation test result to adjust to the optimal printing parameters. According to the method, the geometric features and the material attributes of the 3D model are automatically analyzed, potential weaknesses in the model are identified, and the 3D printing model is intelligently optimized.

The invention provides a curved surface grid generation method based on discrete grid parameterization, and belongs to the technical field of computer aided engineering (CAE) and computational geometry. Aiming at the problems of tedious geometric operation, parameter space fusion distortion, insufficient grid fitness and the like in grid subdivision of a complex curved surface formed by a plurality of sub-curved surfaces, the invention provides the following technical scheme: firstly, carrying out triangular grid pre-subdivision on an original curved surface, and constructing a virtual topological structure for inhibiting non-key features; the discrete grids are mapped to a low-distortion two-dimensional parameter space by adopting least square conformal mapping (LSCM), and seamless combination of multiple sub-surface parameter domains is realized; dynamically calculating a parameter space size field, and controlling grid density distribution; after a parameter space adaptive grid is generated through Delaunay triangulation, grid points are accurately attached to an original geometric surface by using a dual projection correction mechanism. According to the method, complex CAD geometric operation is avoided, the automation degree is remarkably improved, meanwhile, physical space grid uniformity and strict fitness are guaranteed, and the method is suitable for efficient and high-precision grid generation of complex curved surfaces in the fields of aerospace, automobiles, ships and the like.

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 triangular grid mode more reasonably and precisely, so that the capacitor can store more charges.

The invention is suitable for the technical field of garment customization, and particularly relates to a garment customization 3D simulation and process sheet automatic generation method based on artificial intelligence, and the method comprises the steps: providing basic data support through obtaining garment customization parameters; three-dimensional parameter modeling is carried out based on the garment customization parameters, a three-dimensional fitting model corresponding to the garment customization parameters is determined, and the garment upper body effect is visually displayed; performing discrete grid division on the three-dimensional fitting model to obtain a first triangular grid topology corresponding to the three-dimensional fitting model; performing physical constraint iteration on the first triangular mesh topology based on the garment customization parameters to obtain a second triangular mesh topology corresponding to the three-dimensional fitting model; based on the second triangular mesh topology, a customization process sheet corresponding to the garment customization parameters is obtained, simulation and process sheet integration is achieved, the garment making efficiency and quality are effectively improved, and cut-part sewing errors are reduced.

The invention relates to the technical field of motor monitoring, and particularly discloses an intelligent monitoring system based on a rare earth permanent magnet variable frequency motor. A surface-mounted rare earth permanent magnet synchronous motor adopts a surface-mounted design, the motor is embedded into a magnetic material, a rotor and a stator magnetic field operate synchronously during normal work, and a rotor winding has no induced current; rotor resistance and hysteresis loss do not exist, the efficiency of the motor is improved, and the permanent magnet variable frequency motor not only can reduce resistance loss, but also can effectively improve a power factor; magnetic stability analysis, operation simulation and temperature screening are integrated, a section temperature extreme point is excavated, a time sequence trend of the section temperature extreme point is tracked, a core heat source is accurately positioned, and a heat source area is divided according to a preset threshold value based on a triangular mesh, so that real-time identification and partitioning of the internal heat source of the motor are realized, the internal core heat source is accurately positioned, and overheating of a blind area is avoided; and in combination with the temperature-dependent demagnetization boundary, the magnetic safety margin is calculated in real time, early warning or load limiting is performed in time, and irreversible demagnetization is prevented.

The invention discloses an urban rainfall flood simulation-oriented building modeling method based on point cloud data, and belongs to the technical field of urban hydrological modeling, and the method comprises the steps: carrying out the neighborhood search of the rasterized point cloud data, constructing a covariance matrix according to a neighborhood point set, and carrying out the eigenvalue decomposition to obtain a normal vector; plane feature points and slope feature points are determined by extracting vertical components of normal vectors, and then the number of the plane feature points and the number of the slope feature points are counted to determine the building type; projecting the point cloud data to an XOY plane to generate a regularized contour boundary; if the building is a flat roof building, combining the regularized contour boundary with a preset earth surface model to obtain a building model; and if the building is a pitched roof building, constructing a triangular grid through the point cloud data, and combining the triangular grid with a preset earth surface model by using the regularized contour boundary to obtain a building model. According to the method, the problems of low modeling efficiency and geometric distortion caused by incapability of constructing an adaptive model based on a building type in the prior art are solved.

The invention provides a grid reconstruction method and device, electronic equipment and a storage medium. The method comprises the steps of obtaining at least two triangular grid geological curved surfaces; determining triangular pairs in any two triangular mesh geological curved surfaces by adopting a collision detection algorithm; determining an intersection point set and a boundary point set in the triangle pair by adopting an intersection algorithm; determining a topologically ordered intersection line set based on the intersection point set and the boundary point set; and performing grid reconstruction on any two triangular grid geological curved surfaces based on the intersection line set to obtain a reconstructed triangular grid geological curved surface, so that the calculation efficiency of the intersection point can be improved, the intersection result is more accurate, and the reconstructed triangular grid address curved surface can better reflect the topological relation.

The invention discloses an electromagnetic field simulation boundary absorption method and system based on triangular prism grid-FDTD. The method comprises the following steps: constructing an initial triangular prism grid FDTD; virtual points are added in the triangular prism grid FDTD, and MurABC is constructed; and completing boundary absorption in the electromagnetic field simulation process by using MurABC. In the triangular grid, boundary absorption is carried out by intelligently designing the grid structure and the algorithm, the reflection effect can be effectively reduced, and the simulation accuracy is improved. In this way, unnecessary boundary interference can be avoided, and the whole simulation is closer to the actual situation.

The invention discloses a numerical simulation method for a river water and sediment transportation process based on a multi-GPU parallel framework. The method specifically comprises the following steps: dividing a calculation region into triangular grid calculation regions with the same number as GPUs; the variables are initialized; creating two CUDA flows to control parallel calculation of the two GPUs, and storing data of each river channel into the corresponding GPU; directly carrying out data communication between the GPUs; in each GPU, calculating a source item and flux of each triangular grid to obtain a water depth value, and calculating a water level value of each grid according to the water depth; according to the obtained water level value, water level result data calculated in each GPU are stored in a CPU to complete water level data merging; and calculating to obtain the water level values of each river reach and the outlet section of the river at each moment. According to the river sediment transportation process simulation method based on triangular grid multi-GPU parallel computing, the water and sediment transportation process of the river area can be efficiently simulated, and the water level value of the section can be rapidly predicted.

The invention belongs to the technical field of cutting machining, and relates to a cutting simulation blank surface reconstruction method and device and a readable storage medium. Discretizing the tool and the blank to obtain a tool Tri-Dexel model and a blank Tri-Dexel model, and extracting a tool Dexel chain set and a blank Dexel chain set; boolean operation is conducted on the tool Dexcel chain and the blank Dexcel chain, a blank surface voxel model and the cutting condition of the tool Dexcel on all edges of blank surface voxels are obtained, then the state value of all angular points of the blank surface voxels is obtained, and whether the voxels are boundary voxels containing contour surfaces or not is judged; taking the voxel containing the contour surface as a to-be-cut voxel, obtaining a triangular mesh formed by intersection points of the to-be-cut voxel and the contour surface, and calculating vertex coordinates and a normal vector of the triangular mesh; and obtaining a surface grid based on the vertex coordinates and the normal vectors of all the triangular grids so as to perform surface reconstruction on the blank.

The invention relates to the technical field of computer graphics, in particular to a three-dimensional geological section real-time cutting method and system and a storage medium, and the method comprises the steps: constructing a BVH tree to accelerate the cutting of a three-dimensional geological model, and calculating the projection of intersecting line segments on a cutting surface two-dimensional coordinate system to obtain a projection line segment set; constructing an undirected graph structure based on the projection line segment set; and extracting a closed profile contour based on the undirected graph structure, subdividing a triangular grid, and rendering and displaying. The implementation of the scheme can break through the traditional preprocessing dependence, and improve the profile generation efficiency and the visualization integrity.

The invention relates to the technical field of twinborn model construction, in particular to a transformer substation twinborn model construction method based on a VR virtual reality technology, and the method comprises the steps: obtaining dense point clouds of transformer equipment in a transformer substation scene, carrying out the meshing of all dense point clouds, and recording the vertexes of all obtained triangular grids as triangular point clouds; calculating a steep coefficient, a coplanar representation value, local complexity, a degradation evaluation value and a degradation contribution degree of each triangular grid; determining a distortion evaluation value; and for the distribution position of each trigonometric point cloud on the transformer equipment, determining the reconstruction weight of each trigonometric point cloud, performing three-dimensional reconstruction on the transformer equipment in the transformer substation scene, and constructing a transformer substation twinborn model. The transformer equipment twinborn model in the transformer substation scene is closer to the original condition, small and medium-sized equipment in the transformer substation scene is modeled more finely, and the visualization effect of the transformer substation twinborn model is improved.

The invention relates to the field of three-dimensional industrial software, in particular to a method and equipment for measuring a lightweight model in cutting simulation and a storage medium. Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects: the correctness advantage is that the randomness of local sampling of triangular mesh vertexes in a traditional method is avoided through a method of geometric fitting of data in a continuous instruction of an NC code and analysis and extraction of processing features; the types and basic data of the processing features can be more accurately obtained. The processing speed has the advantages that the problem of low efficiency of identifying features according to a large amount of geometric information in a lightweight model in a traditional method is avoided through a method of geometric fitting of data in continuous instructions of NC codes and analysis and extraction of processing features, and the NC codes may already contain basic data of the features; and the process of calculating the feature size by the measurement function can be reduced in a manner of associating the triangular mesh with the feature basic data.

A 3D dense surface element mapping method based on SLAM and its system and electronic device. The 3D dense surface element mapping method based on SLAM includes the following steps: pre-processing the incoming image frame data and posture data to obtain synchronized image frame posture information and corresponding image information, wherein the image information includes aligned grayscale images and depth images; performing superpixel segmentation, surface element extraction and fusion processing on the image information in combination with the image frame posture information in the same thread to obtain an updated surface element map; and performing structured mesh processing on the updated surface element map to output the triangular mesh data of the dense map in real time.

The invention discloses a three-dimensional modeling method for a transformer substation. The method comprises the following steps: acquiring image data information of a target transformer substation by adopting an unmanned aerial vehicle; performing feature point extraction and feature point matching on the image data information; performing aerial triangulation to obtain three-dimensional data information of the feature points; performing multi-view image dense matching to obtain global dense point cloud data of the target substation, and obtaining a global coarse model based on oblique photography; constructing a point cloud classification model and extracting local features of the equipment; carrying out refined point cloud completion on the equipment based on the high-precision three-dimensional model of the neural radiation field; constructing an irregular triangular grid to obtain a fine model of the target substation equipment; and three-dimensional modeling of the target transformer substation is completed through the model obtained through fusion. The invention also discloses a system for realizing the three-dimensional modeling method of the transformer substation. According to the method, refined three-dimensional modeling of the target transformer substation is realized, the reliability is higher, and the accuracy is better.

The invention discloses a dual circularly polarized phased-array antenna based on triangular grid arrangement. A phased-array antenna module sub-array is formed by triangular grid arrangement of phased-array antenna units; the radiation unit adopts a cross oscillator with a gradual change structure, the impedance matching is improved, and a feed network of a three-branch linear bridge is matched, so that the impedance bandwidth of the antenna is improved, and the requirements of more communication frequency bands are met; the orthohexagonal antenna unit appearance and the metal partition wall are adopted, so that mutual coupling between the antenna units is reduced, and the isolation degree between the antenna units and the overall performance are improved; triangular grid arrangement is adopted, and the problems that the scanning range of a traditional rectangular array is limited, and grating lobes are prone to occurring during large-angle scanning are solved; the device has higher polarization purity and lower cross polarization level, supports quick splicing of N * N subarrays, and has the advantages of simple structure, low cost and easiness in processing.

The invention provides an intelligent grading identification method for a potential infiltration risk area of a drainage pipe network, and relates to the technical field of risk identification of the drainage pipe network. Establishing spatial relation mapping between triangular grid units of the surface water-underground water coupling model and pipe sections of the drainage pipe network model, calculating hourly liquid level difference time sequence data by utilizing underground water level time sequence data and corresponding pipe section liquid level time sequence data which are obtained through simulation calculation, and constructing risk indexes according to the hourly liquid level difference time sequence data; and then constructing an uncertainty scene sample set and respectively inputting the two models to obtain corresponding simulation calculation results, calculating to obtain a risk index corresponding to each pipe section, and judging a grading result of a potential infiltration risk area according to the risk indexes. Simulation calculation and intelligent diagnosis analysis are fused, and efficient identification of the potential infiltration risk area of the drainage pipe network is achieved on the premise that large-scale sensor deployment is not needed.

The invention provides an endoscope image processing method and device, equipment and a storage medium, relates to the field of image processing, and is used for improving the display effect of an endoscope image. The method mainly comprises the following steps: acquiring a spinal endoscope image from a spinal endoscope video stream; filtering the spinal endoscope image according to the time information, the angle information and the position information of each frame of spinal endoscope image; performing image preprocessing on each frame of filtered spine endoscope image, and inputting the spine endoscope image subjected to image preprocessing into a spine recognition model to obtain a spine position area corresponding to each frame of spine endoscope image; extracting a spine structure image from the spine endoscope image according to the spine position area; projecting position information and depth information of each pixel point in each frame of spine structure image to a corresponding position in a three-dimensional space to form point cloud data; and converting the point cloud data into triangular grids to obtain an endoscope image three-dimensional model of the spine.

The invention discloses a mixed three-dimensional data processing method and device, a program product and a storage medium, and relates to the technical field of three-dimensional data processing, and the method comprises the steps: obtaining scene data and rendering parameters; for any rendering pixel, determining an intersection point of the projected light and the nearest object surface in the first object set after the projected light is emitted; performing color accumulation on the path of the projection light through the three-dimensional data in the neural network format to obtain the path color of the projection light, and superposing the path color of the projection light with the initial color of the projection light and the color of the three-dimensional data in the triangular grid format at the final position of the projection light to obtain the initial color of reflected light; and taking the reflected light as the projection light to continue iteration to obtain the final color of the rendering pixel, and generating a rendering image based on the final color of each rendering pixel. The problem that processing of heterogeneous three-dimensional data is not supported is solved, and the technical effect of effectively rendering the heterogeneous mixed three-dimensional data including the triangular mesh data and the three-dimensional data based on the neural network is achieved.

A robot spraying control method and system based on digital twins, including the following steps: constructing a three-dimensional model of a workpiece and a robot to be sprayed, wherein the three-dimensional model of the workpiece is composed of a triangular mesh; meshing the triangular mesh of the three-dimensional model of the workpiece to obtain a refined first model; constructing a BVH data structure, and storing the triangular mesh parameters in the first model through the BVH data structure; setting the spray gun parameters and the thickness color table of the workpiece, wherein the spray gun parameters are the spray flow rate and the fog cone angle; after the workpiece collides with the nozzle ray, the dyeing thickness of each triangular mesh in the spraying is calculated, and the three-dimensional model of the workpiece is assigned color through the dyeing thickness and the thickness color table. By constructing a three-dimensional model of the workpiece and the robot, encapsulating the robot parameters, and having precise point coordinates, the robot posture and parameters can be adjusted better and more conveniently. The problem of difficulty in debugging the spray robot is solved.

The invention relates to the technical field of intelligent power transmission and distribution line emergency lighting and unmanned aerial vehicle dynamic deployment optimization, and discloses a power transmission and distribution line emergency repair lighting system and method based on wireless networking unmanned aerial vehicle lighting. Establishing a two-dimensional coordinate and an equilateral triangle mesh, and taking a center coordinate; setting the upper limit and height of the unmanned aerial vehicle, establishing an illumination cone, obtaining a light spot radius according to an opening angle, and comparing a grid distance with the radius to judge that irradiation can be performed; the illuminance is accumulated and compared with a threshold value to reach the standard; taking a substandard proportion as a target and setting an overlapping proportion and a safety center distance as constraints; assuming the candidate points one by one, deploying the maximum gain, heightening or adjusting the angle of the gap area and rechecking the constraint; calculating a link threshold according to field parameters to construct an ad hoc network, and selecting a relay to recover disconnection; performing balanced scheduling by using the average deviation and the neighborhood positive gap after the global standard is reached; and finally activating the recording parameters and summarizing the situation map.

The present invention proposes a method for generating a panoramic image of a cylindrical mural, comprising the following steps: Step 1: using a three-dimensional reconstruction method to restore the original three-dimensional scene of the target object; Step 2: reading and processing the data in the PLY file; Step 3: calculating the parameter information of the ideal cylindrical surface closest to the cylindrical surface through a sampling consistency algorithm; Step 4: mapping the model to the ideal cylindrical surface according to the obtained parameter information; Step 5: segmenting the triangular mesh of the closed model and unfolding it to a plane; Step 6: finally projecting it into a panoramic digital image stored in a BigTIFF file. The present invention solves the problem that the traditional method can only handle the preservation of planar murals but cannot preserve murals on curved surfaces such as cylinders.

The present invention relates to the field of nuclear power engineering, namely the placement of unsheathed fuel assemblies in a nuclear reactor core, aiming to improve the heat dissipation of fuel elements in a nuclear reactor. The nuclear reactor core comprises a hexagonal unsheathed fuel assembly having fuel elements located on a triangular grid with a spacing greater than the diameter of the fuel element cladding. The fuel elements comprise spiral spacer ribs on the cladding and are rigidly fixed in a given angular direction so that the fuel elements are in rib-to-rib contact at a height position at which the fuel elements reach the maximum fuel element cladding temperature during reactor operation. The fuel assembly is positioned in such a way that the fuel elements located on the surface of the fuel assembly form a single triangular grid with the remaining fuel elements in the core, and ensure that all the fuel elements are in rib-to-rib contact at a height position at which the highest fuel element cladding temperature is reached during reactor operation. At the same time, incorrect placement of the fuel assembly in the core is eliminated.