ACCOUNTING THE DIRECTIONAL DIAGRAM OF THE ON-BOARD ANTENNA IN ANALYSIS OF THE COMMUNICATION CHANNEL WITH THE AIRCRAFT

2021 ◽  
pp. 118-122
Author(s):  
С.В. Кузьмин ◽  
К.О. Коровин ◽  
А.В. Андропов
Keyword(s):  
Radiation Pattern ◽  
Computer Aided Design ◽  
Communication Channel ◽  
Directional Pattern ◽  
Directional Diagram ◽  
Modern Computer ◽  
Real Objects ◽  
The Media ◽  
Design Systems ◽  
Aided Design

Синтез оптимальной с точки зрения дальности диаграммы направленности является одной из основных задач построения канала связи. Для многих приложений, таких как 2D вторичный локатор, канал связи с БЛА, оптимальной является косекансная диаграмма направленности. В первом приближении антенна, установленная на борту, обладает практически постоянным коэффициентом усиления в направлении на стационарную антенну. Характеристики бортовой антенны получаются из решения задачи в свободном пространстве. Учёт рассеивающих свойств объектов сложной геометрической формы с размерами в десятки длин волн является актуальной, но сложной задачей. При перемещении по поверхности носителя диаграмма направленности бортовой антенны может меняться существенным образом. Современные системы автоматизированного проектирования на основе приближённых численных методов электродинамики позволяют получать характеристики антенн, размещённых на реальных объектах. Ввиду увеличения количества полезных нагрузок на борту не всегда удаётся разместить бортовую антенну в таком месте, которое позволяет пренебречь влиянием геометрии носителя. В результате в диаграмме направленности бортовой антенны появятся интерференционные провалы или минимумы. Дальность работы будет зависеть от перемещения носителя. Рассматривается метод учета характеристик ДН бортовой антенны, позволяющий минимизировать запас на замирания The synthesis of the optimal, in terms of range, directional pattern is one of the main tasks of building a communication channel. For many applications, such as a 2D secondary locator, a communication channel with a UAV, the cosecant radiation pattern is optimal. As a first approximation, the on-board antenna has an almost constant gain towards the stationary antenna. The characteristics of the onboard antenna are obtained by solving the problem in free space. Taking into account the scattering properties of objects of complex geometric shapes with dimensions of tens of wavelengths is an urgent but difficult task. When moving over the surface of the carrier, the radiation pattern of the onboard antenna can change significantly. Modern computer-aided design systems based on approximate numerical methods of electrodynamics make it possible to obtain the characteristics of antennas placed on real objects. Due to the increase in the number of payloads on board, it is not always possible to place the onboard antenna in such a place that makes it possible to neglect the influence of the carrier geometry. As a result, interference dips or minima will appear in the directional pattern of the onboard antenna. The operating range will depend on the movement of the media. We considered a method for taking into account the characteristics of the antenna pattern of an airborne antenna, which allows minimizing the margin for fading

scholarly journals CAR MANIPULATOR IMITATION MODEL IMPLEMENTED IN CAD ENVIRONMENT

2020 ◽  
Vol 9 (4) ◽  
pp. 142-150
Author(s):  
P. Popikov ◽  
Vladimir Zelikov ◽  
Konstantin Yakovlev ◽  
K. Menyaylov ◽  
Mikhail Shabanov ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Simulation Model ◽  
Programming Languages ◽  
Analytical Methods ◽  
Computer Aided Design ◽  
Lagrange Equations ◽  
Modern Computer ◽  
Computer Aided ◽  
Design Systems ◽  
Aided Design

The article is devoted to the problems of simulation of the working process of a truck-mounted crane using modern computer-aided design systems and applications for engineering calculations. Currently, analytical methods are mainly used to model the operation of manipulator technology, such as “manual” compilation and solution of Lagrange equations of the second order, or even simpler evaluative calculations based only on basic concepts of theoretical mechanics. However, such objects consist of many parts that are in a complex rotational motion and contact interaction with each other. If such complex systems are modeled by the indicated analytical methods, one has to introduce a number of assumptions that greatly simplify the mathematical model. The level of its adequacy is low. Also recently, numerical methods for modeling mechanisms that are implemented through programming languages by using a detailed description of the process under study are often used abroad. An alternative to these methods is the use of computer-aided design systems in which numerical methods are built-in at the core level of the program and require setting the basic geometric, dynamic and kinematic parameters of the mechanism and the environment, after which they can calculate the functioning parameters of the object under study. The process of creating a simulation model of a truck mounted crane, which is an analogue of an existing laboratory setup, has been considered. To do this, a 3D model of the manipulator in the SolidWorks CAD environment has been developed. The creation technique and the main features of the obtained simulation model have been described

Low-fidelity prototyping with simple collaborative tabletop computer-aided design systems

2018 ◽  
Vol 70 ◽  
pp. 307-315 ◽  
Author(s):  
Erdem Kaya ◽  
Sema Alacam ◽  
Yasin Findik ◽  
Selim Balcisoy
Keyword(s):  
Computer Aided Design ◽  
Computer Aided ◽  
Design Systems ◽  
Aided Design

Development of computer-aided design systems for metal-forming processes

1989 ◽  
Vol 21 (3) ◽  
pp. 185
Author(s):  
Y. Mitani ◽  
H.R.R. Merchand ◽  
E. Velazquez
Keyword(s):  
Metal Forming ◽  
Computer Aided Design ◽  
Computer Aided ◽  
Design Systems ◽  
Aided Design

Capturing and Using Designer Intent in a Design-With-Features System

1991 ◽  
Author(s):  
Eric H. Nielsen ◽  
John R. Dixon ◽  
George E. Zinsmeister
Keyword(s):  
Computer Aided Design ◽  
Simultaneous Equation ◽  
The Core ◽  
Knowledge Based ◽  
Evaluation Procedures ◽  
Equation Solving ◽  
Feature Based ◽  
Design Systems ◽  
Aided Design ◽  
Intelligent Computer

Abstract The goal of “intelligent” computer-aided-design (CAD) systems is to provide greater support for the process of design, as distinguished from drafting and analysis. More supportive design systems should provide a quick and simple means of creating and modifying design configurations, automating evaluation procedures (e.g., for manufacturing), and automating interfaces to analysis procedures. In this paper we are concerned with the issues of representing in-progress designs so that such goals can be met. A feature-based representation is proposed in which features are defined as possessing not only form but also certain designer intentions regarding geometric relationships. A working experimental version of a design-with-features system using this representation for thin-walled components illustrates its use in composing a design as a configuration of feature-forms, in modifying the design geometry through automatic, intelligent incorporation and propagation of designer-initiated geometry changes, and in providing for the generation of user-defined features. In contrast to constraint-driven simultaneous equation solving methods, this system uses an intent-driven knowledge-based method to propagate and incorporate geometry modifications not only in fully-constrained designs, but also in over- and under-constrained designs. Issues of manageability, extensibility, and computationally efficiency were considered in the development of the core services of the system.

CAD in the CIM Environment: Where Do We Go From Here?

1986 ◽  
Vol 39 (9) ◽  
pp. 1345-1349 ◽  
Author(s):  
Dell K. Allen ◽  
W. Van Twelves
Keyword(s):  
Computer Aided Design ◽  
Material Selection ◽  
Operating Conditions ◽  
Computer Integrated Manufacturing ◽  
Accurate Information ◽  
Functional Requirements ◽  
Essential Information ◽  
Design Systems ◽  
Aided Design ◽  
Product Definition

The importance of computer-aided design (CAD) has not been fully appreciated as it relates to computer integrated manufacturing (CIM). The CAD product definition model can provide essential information for many down-stream production, estimating, tooling, and quality assurance functions in the CIM environment. However, the product definition model may be inaccurate or incomplete, thus causing incomplete communication with possible scrap, re-work, and missed production deadlines. Other problems are related to the fact that many of our expert designers are retiring and taking their expertise with them. Merely being able to make 2D or 3D drawings on a CAD workstation does not make its operator a designer. A knowledge of production processes, tolerances, surface finish, and material selection is needed to supplement a designers knowledge of user needs, product functional requirements, operating conditions, cost, quality, and reliability targets. One of the most promising methods for providing timely and accurate information to the designer on an “as-needed” basis is through the use of expert design systems. Such systems promise to bridge the knowledge gap between CAD and CAM and help to incorporate these functions into the overall CIM environment.

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