scholarly journals Automation of the inner design of the aircraft

2019 ◽  
Vol 11 (S) ◽  
pp. 135-141
Author(s):  
Mikhail Yu. KUPRIKOV ◽  
Leonid V. MARKIN
Keyword(s):  
Design Automation ◽  
Geometric Modeling ◽  
Virtual Prototyping ◽  
Practical Implementation ◽  
Cad Systems ◽  
Geometric Models ◽  
Modern Computer ◽  
Modeling Systems ◽  
Swept Surface ◽  
Blind Search

The task of forming the wind-swept surface according to the results of the aircraft’s inner design is described. The approach of the integration of natural and virtual prototyping in the design of equipment compartments is substantiated. Such approaches open up new possibilities for creating intelligent composition algorithms that eliminate the "blind search". For the practical implementation of these approaches, it is necessary to link the appropriate software to standard geometric modeling systems in the form of additional computational modules. Preparing the aircraft for design automation complicates the mathematical description of geometric models of placed objects, increases the complexity of their visualization in modern computer graphics systems and the need to create an additional interface between new geometric models and common CAD systems (SolidWorks, AutoCAD, COMPAS, etc.).

scholarly journals Method of formalizing the layout of the internal compartments of aircraft

2019 ◽  
Vol 11 (S) ◽  
pp. 143-152
Author(s):  
Mikhail Yu. KUPRIKOV ◽  
Leonid V. MARKIN
Keyword(s):  
Optimization Problem ◽  
Mathematical Formulation ◽  
Performance Criteria ◽  
Layout Problem ◽  
Intelligent Algorithms ◽  
Cad Systems ◽  
Geometric Models ◽  
Modern Computer ◽  
And Performance ◽  
Automated Placement

The mathematical formulation of the aircraft’s internal layout problem is described as an optimization problem, with an indication of its objective function, constraints, and performance criteria. The approach (receptor methods and apparatus of normal equations) is justified, which makes it possible to move from enumeration method of placing added objects to intelligent algorithms of automated placement when creating geometric models of automated layout. It was shown that preparing the aircraft for layout automation complicates the mathematical description of geometric models of added objects, increases the complexity of their visualization in modern computer graphics systems and makes the need to create an additional interface between new geometric models and common CAD systems (SolidWorks, AutoCAD, COMPAS, etc.).

Reconstruction of Quadratic Cremona Transformation

2017 ◽  
Vol 5 (2) ◽  
pp. 59-68
Author(s):  
Короткий ◽  
Viktor Korotkiy
Keyword(s):  
Geometric Modeling ◽  
The Other ◽  
Practical Implementation ◽  
Cremona Transformation ◽  
Quadratic Transformation ◽  
Modern Computer ◽  
Set Up ◽  
The One ◽  
Straight Lines ◽  
Base Data

The geometric correspondence between the points of two planes can be considered well defined only when base data for its establishing is available, and a construction method by which its possible on the basis of these data for each point in one plane to find the corresponding points in the other one. Quadratic Cremona transformation can be specified by pointing out in the combined plane seven pairs of corresponding points. Naturally there is a need to establish a method for constructing any number of corresponding points. An outstanding Russian geometer K.A. Andreev indicated the linear construction based on the consideration of two correlations by which for each eighth point in the one plane is found the corresponding point of the other one. But in his work was not set up a problem to construct excluded (fundamental) points of quadratic Cremona transformation specified by seven pairs of points. There are many constructive ways to obtain the quadratic transformation in the plane. For example, it can be obtained by using two pairs of projective pencils of straight lines with vertices at the fundamental points (F-points). K.A. Andreev noted that this method for establishing of quadratic correspondence spread only to those cases when all F-points are the real ones. This statement is true for the 19th century’s level of geometric science, but today it’s too categorical. The theory of imaginary elements in geometry allows to develop a universal algorithm for construction of corresponding points in a quadratic transformation, given both by real and imaginary F-points. Summarizing the K.A. Andreev task, we come to the problem of finding the fundamental points (F-points) for a quadratic transformation specified by seven pairs of corresponding points. Almost one and half century the K.A. Andreev generalized task remained unsolved. The formation of this task’s constructive solution algorithm and its practical implementation has become possible by means of modern computer geometric modeling. According to proposed algorithm, the construction of F-points is reduced to the construction of second order auxiliary curves, on which intersection are marked the required F-points. The result received in this paper is used for development of the Cremona transformations’ theory, and for further application of this theory in the practice of geometric modeling.

scholarly journals Hardware and Software Implementation of Constructive Geometric Models

2020 ◽  
pp. 83-98
Author(s):  
Denis Voloshinov ◽  
Konstantin Solomonov
Keyword(s):  
Computer Technology ◽  
Geometric Modeling ◽  
Software Implementation ◽  
Theoretical Research ◽  
Graphical Interface ◽  
Calculation Methods ◽  
Geometric Transformations ◽  
Geometric Models ◽  
Long Time ◽  
Geometric Modeling System

The article is devoted to the consideration of a number of issues of hardware and software implementation of constructive geometric models. A rich arsenal of theoretical research in the field of constructive geometry has not been properly used for a long time due to the lack of tools for translating such models using computer technology. The development and improvement of the Simplex geometric modeling system, in which any geometric design is considered as a converter of information represented by signals of a geometric nature, has opened the possibility of applying the achievements of geometric science in computing applications, as well as the development of hardware that implements geometric calculation methods and provides a new graphical interface. The concept developed by the authors is aimed at creating specialized accelerators of geometric transformations.

Development of an Image-Based CAD Using Wavelet Transform

2000 ◽  
Author(s):  
Soonkyu Yim ◽  
Hae Chang Gea
Keyword(s):  
Wavelet Transform ◽  
Geometric Modeling ◽  
Haar Wavelet ◽  
Layered Manufacturing ◽  
File Size ◽  
Modeling Tools ◽  
Data Format ◽  
Haar Wavelet Transform ◽  
Cad Systems ◽  
Cad Models

Abstract Traditionally, designers describe features of objects from various geometric modeling tools. However, a geometry-based system requires complex mathematical formulations and data structures that make it very cumbersome to manipulate. Furthermore, Layered Manufacturing (LM) has become a prominent manufacturing technology in recent years. To support LM under geometry based CAD systems, users have to slice the model into layers. It is obvious that geometric characteristics of the geometry-based CAD models are destroyed during these conversions, at the same time, additional efforts and costs will be accumulated. To bridge the gap between CAD and LM, an image-based data format instead of a geometry based data format is proposed to serve as the foundation of CAD systems in this paper. A wavelet transform is used to reduce the file size and produce multi-resolution image map. To further increase the computational efficiency of the algorithm, we developed the Reduced Haar Wavelet transform and a bit-remainder index.

Maintenance of Geometric Representations Through Space Decompositions

1997 ◽  
Vol 07 (01n02) ◽  
pp. 21-56 ◽  
Author(s):  
Vadim Shapiro
Keyword(s):  
Geometric Modeling ◽  
Systematic Approach ◽  
Multiple Representation ◽  
Modeling Systems ◽  
Geometric Representations ◽  
Representation Scheme

The ability to transform between distinct geometric representations is the key to success of multiple-representation modeling systems. But the existing theory of geometric modeling does not directly address or support construction, conversion, and comparison of geometric representations. A study of classical problems of CSG ↔ b-rep conversions, CSG optimization, and other representation conversions suggests a natural relationship between a representation scheme and an appropriate decomposition of space. We show that a hierarchy of space decompositions corresponding to different representation schemes can be used to enhance the theory and to develop a systematic approach to maintenance of geometric representations.

Construction of Receptor Geometric Models for Objects of Complex Technical Forms

2020 ◽  
Vol 7 (4) ◽  
pp. 44-56 ◽  
Author(s):  
Vin Tun E ◽  
Leonid Markin
Keyword(s):  
Solid State ◽  
Geometric Modeling ◽  
Parametric Models ◽  
State Model ◽  
Universal Method ◽  
Receptor Model ◽  
Geometric Models ◽  
Cad System ◽  
Receptor Models ◽  
Single Receptor

In this paper the question related to the use of receptor (voxel) method for geometric modeling to solve practical design problems has been considered. The use of receptor methods is effective in solving a certain class of problems, primarily the problems of automated layout. The complexity of this method’s practical use is due to the fact, that receptor geometric models are never the primary ones. They are formed based on parametric models specified by designer. Receptor models are the internal machine ones. The main problem that prevents the widespread use of the receptor method is the lack of universal methods for converting parametric models into the receptor ones. Available publications show that in solving practical problems various authors have developed their own methods for creating receptor models for objects of "primitives" and "composition of primitives" classes. Therefore, it is extremely urgent to solve the problem of developing a universal method of forming receptor models for objects of complex technical forms. The essence of the proposed method is the transformation of a solid-state model created in a CAD system into a receptor matrix. First in the physical one, in which the solid-state model is discretized into cubes with receptor sizes, and then in the mathematical one — a three-dimensional array with binary codes of zeros and ones. The creation of a physical receptor matrix is carried out by means of the CAD-system itself, allowing diagnose the belonging of a single receptor to a simulated object. The fact of intersection or non-intersection a given position by a single receptor is encoded by "1" and "0" respectively, and this information is transferred to a mathematical receptor model (3-dimensional binary array). This calculation procedure is programmed in the form of a macro, providing a given position of a single receptor and fixing the fact of its intersection with the solid-state model. Have been demonstrated examples for described method’s practical application, and has been carried out CPU time cost estimation for the construction of a physical receptor model depending on the receptor size and object geometric complexity. Actions on data transformation from a solid-state model to a receptor one have been implemented in the form of C# programs.

scholarly journals Analysis of Microstructure Images Referred to Percolation Theory

2015 ◽  
Vol 15 (1) ◽  
pp. 109-112 ◽  
Author(s):  
W. Trzaskowski ◽  
W. Sobaszek ◽  
D. Myszka ◽  
S. Świłło
Keyword(s):  
Percolation Theory ◽  
Spatial Arrangement ◽  
Polycrystalline Materials ◽  
Practical Implementation ◽  
Material Structure ◽  
Two Phase ◽  
Modern Computer ◽  
Planar Images ◽  
Metallographic Image Analysis

Abstract The paper discusses possible applications of the percolation theory in analysis of the microstructure images of polycrystalline materials. Until now, practical use of this theory in metallographic studies has been an almost unprecedented practice. Observation of structures so intricate with the help of this tool is far from the current field of its application. Due to the complexity of the problem itself, modern computer programmes related with the image processing and analysis have been used. To enable practical implementation of the task previously established, an original software has been created. Based on cluster analysis, it is used for the determination of percolation phenomena in the examined materials. For comparative testing, two two-phase materials composed of phases of the same type (ADI matrix and duplex stainless steel) were chosen. Both materials have an austenitic - ferritic structure. The result of metallographic image analysis using a proprietary PERKOLACJA.EXE computer programme was the determination of the content of individual phases within the examined area and of the number of clusters formed by these phases. The outcome of the study is statistical information, which explains and helps in better understanding of the planar images and real spatial arrangement of the examined material structure. The results obtained are expected to assist future determination of the effect that the internal structure of two-phase materials may have on a relationship between the spatial structure and mechanical properties.

An Approach for Generating Variational Geometry of a Pattern of Holes With Composite Positional Tolerances

2002 ◽  
Author(s):  
Y. S. Liu ◽  
S. M. Gao
Keyword(s):  
Mathematical Models ◽  
Geometric Modeling ◽  
Mechanical Design ◽  
Cad Systems ◽  
Computer Aided ◽  
Cad Cam ◽  
Positional Tolerance

In most present CAD systems, the accurate geometry representation of a part is given but the tolerance is just a text attribute without semantics. It hampers the integration of CAD/CAM. In last two decades, much research has been conducted on computer aided tolerancing. And many approaches to generation of variational geometry for various kinds of features have been given. However how to generate the variational geometry of a pattern of holes (POH) is not well studied yet although a POH is one of the most widely-used features in mechanical design. Based on DOF, an approach is proposed for generating variational geometry of a POH with composite positional tolerance in this paper. First, the limitation conditions for variations of a POH are given. Second, the mathematical models of translational and rotational variations are systematically derived. Then the algorithm for generating variational geometry of a POH is given. At last the proposed approach has been implemented with Visual C++ based on the geometric modeling kernel ACIS5.0.

On the Peculiarities of the Constructive Solution For Dandelin Spheres Problem

2018 ◽  
Vol 6 (2) ◽  
pp. 55-62 ◽  
Author(s):  
Д. Волошинов ◽  
Denis Voloshinov
Keyword(s):  
Design Automation ◽  
Geometric Modeling ◽  
Traditional Approach ◽  
Geometric Theory ◽  
Systems Design ◽  
Geometric Approach ◽  
Practical Significance ◽  
Problem Solution ◽  
Functional Capabilities ◽  
Classification Feature

This paper is devoted to analysis of Dandelin spheres problem based on the constructive geometric approach. In the paper it has been demonstrated that the traditional approach used to this problem solving leads to obtaining for only a limited set of heterogeneous solutions. Consideration of the problem in the context of plane and space’s projective properties by structural geometry’s methods allows interpret this problem’s results in a new way. In the paper it has been demonstrated that the solved problem has a purely projective nature and can be solved by a unified method, which is impossible to achieve if conduct reasoning and construct proofs only on affine geometry’s positions. The research’s scientific novelty is the discovery and theoretical justification of a new classification feature allowing classify as Dandelin spheres the set of spheres pairs with imaginary tangents to the quadric, as well as pairs of imaginary spheres with a unified principle for constructive interrelation of images, along with real solutions. The work’s practical significance lies in the extension of application areas for geometric modeling’s constructive methods to the solution of problems, in the impro vement of geometric theory, in the development of system for geometric modeling Simplex’s functional capabilities for tasks of objects and processes design automation. The algorithms presented in the paper demonstrate the deep projective nature and interrelation of such problems as Apollonius circles and spheres one, Dandelin spheres one and others, as well as lay the groundwork for researches in the direction of these problems’ multidimensional interpretations. The problem solution can be useful for second-order curves’ blending function realization by means of circles with a view to improve the tools of CAD-systems’ design automation without use of mathematical numerical methods for these purposes.

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