2011. № 48
Mathematics. Physics. Mechanics | |
The article uses a combined method of investigation of the dynamic behavior of anisotropic cylindrical shell reinforced by irregular set of circular ribs, which allows to obtained an analytical solution for a system of different eguations in partial derivaties. Keywords: Thin circular anisotropic cylindrical shell, aхcess pressure, uniform acceleration, the average speed, natural modes of vibration, dynamicity coefficient |
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In work any stage of interaction of absolutely firm indenter and elastic isotropic homogeneous half-space within the limits of a plane problem of the theory of elasticity is considered. The non-stationary contact problem is shown to system of the functional equations (SFE), containing multiple singular integrated equation of type of Voltaire of I kind which kernel are superficial functions of influence for an elastic half-plane. For decision SFE the method of grids for existential area of contact [1, 2], modified for multicoherent areas of contact and spline-parameterizations directing the drummer is used. Examples of the decision of contact problems for the elliptic indenter with initial imperfections are resulted. The considered approach is used in problems of dynamics of a landing of lowered space vehicles on rocky. Keywords: non-stationary contact problems; an elastic half-plane; absolutely firm body; multicoherent area of contact; existential area of contact; the elliptic indenter; the B-spline; contact stress |
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Aviation technics and technology | |
Optimal path planning for monitoring of highways and ground static targets by unmanned aerial vehicle is considered in the paper. The optimal conditions of switching from the flight under the highway on the flight to neighboring ground target are defined. The obtained conditions allow planning UAV flight at joint monitoring of both long-distance highways and group of the ground targets. Keywords: unmanned aerial vehicle; path planning; highway monitoring; observation |
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The article discusses assessment of an object position at a given location of a layout based on the optimal conditions of maintainability, removability and interchangeability. There are also considered cases of comparison of the object layout in a specified cell with accepted failure parameters. The basic comparative criteria is the correlation coefficient between the availability (the geometric component of the layout decision), and service parameters. The designed calculation module is part of a program to create an optimal layout solution for a newly designed item. Keywords: layout, correlation coefficient, reliability of results, Harrington's desirability index |
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Aerospace propulsion engineering | |
Takeoff thrust management parameters such as initial altitude and lapse rate of thrust throttling were optimized in the work. It was shown, that the optimization under given market requirements to supersonic business jet may significantly increase the feasibility of design, identify effective ways to meet strong mission and environmental restrictions. Optimization of main engine and aircraft design variables such as bypass ratio, overall pressure ration, turbine inlet temperature at takeoff, etc. were additionally considered for maximal increase of takeoff thrust management efficiency. Keywords: supersonic business jet, throttling, jet noise, flight trajectory, mission performance. |
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Research concerns area of automation of technological preparation of assembly manufacture in aircraft construction. The algorithm of formation of a choice of technological operations is offered at assembly of knot of a glider of the plane on the basis of use of an image of a product. The description of objects of the industrial environment and their interrelation is executed in the form of teoretiko-plural model. Keywords: assembly; designing; technological process; an image of a product; the knowledge bas |
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Control systems | |
The paper describes the technique of pair-wise comparison of guidance systems guided air bombs. As the performance criteria were used, describing the beneficial effects from the use of guided air bombs, and the possibility of reflecting around the clock and all-weather use. Account of the basic performance criteria can adequately describe the quality of guidance system in a hierarchical structure guided air bombs complex aircraft armament and create a priority number of alternative guidance systems. Keywords: guidedbomb, complex aircraft armament, guidance system, the criterion of efficiency, the method of analysis of hierarchies |
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This article is about the algorithm for finding optimal solution of the problem of high precision homing on the terminal part of the trajectory for high-speed aeroballistic unmanned aerial vehicle (UAV) with high aerodynamic efficiency into the atmosphere. The described algorithm, in essence, is solution for nonlinear optimal control problem with some of unique features. The mentioned problem is complicated by the uncertainties of aerodynamic characteristics of the aircraft and the wide range of uncontrolled effects of the different nature. The algorithm generates aboard continuously updateable optimal trajectory in the form of numerical determination of control inputs have obtained by variational methods according to the data from the multispectral surveillance system. The problem is solving within following constrains: on accuracy, absolute value and orientation of the velocity vector at the end of the path, total waste of control actions and resolution of the multispectral surveillance system. Simulation results show us the applicability of the proposed algorithm for generation of optimal control actions in different conditions with the low sensitivity to the effects of uncontrollable factors. Keywords: high precision homing; updateable optimal trajectory; genetic algorithm; criteria Boltz; high-speed aeroballistic UAV |
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In this article the approach is provided to solve the problem of determining homing method meeting requirements of accuracy with the constraints imposed on the terminal part of trajectory for the high-speed aeroballistic unmanned aerial vehicle (UAV) with the high aerodynamic efficiency into the atmosphere. The problem is complicated by the uncertainties of aerodynamic characteristics of the aircraft and the wide range of uncontrolled effects of the different nature. The algorithm generates aboard continuously updateable reasonable trajectory according to the data from the multispectral surveillance system. The results of modelling show us the applicability of the proposed approach for generation of optimal control actions in different conditions with low sensitivity to the effects of uncontrollable factors. Keywords: high precision homing; updateable reasonable trajectory; spline; Bezier curve; high-speed aeroballistic UAV |
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Navigation systems | |
The article is devoted to a substantiation of structure of the navigation system of small shock unmanned aerial vehicle (UAV) of the average duration of the flight, which belongs to the class of remotely operated aircraft systems and which is intended for destruction of ground-based small-size targets. The article considers the problems solved by UAV, methods of navigation and navigation systems, capable to solve tasks assigned to the system. On the basis of the analysis of opportunities, merits and demerits of modern navigation systems the author makes a conclusion that for the implementation of all the requirements, which must meet an UAV, it shall be equipped with combined system of navigation, which implements the principles of complex processing of information. Keywords: an unmanned aerial vehicle, a structure, a combined system,аcomplexing, a semi-automatic system, an operator, a noise immunity. |
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Instrument making | |
The article deals with the development of portable speckle – interferometer not needing complicated adjustment allowing subject vibration characteristics study without using interferometric table. Speckle – interferograms of compressor stage 7 blade vibration modes obtained with smooth base wave interferometer and those ones obtained with portable speckle – interferometer were compared. Identity of obtained results is shown. Vibration characteristics of parts of compressor wheel and turbine nozzle vane unit were investigated with the portable speckle – interferometer. Keywords: vibration modes; speckle – interferometry; laser speckles; holographic interferometry. |
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Radio engineering. Electronics. Telecommunication systems | |
The multichannel hardware-software device has been developed. It guarantees collection and processing of data with high quality. The standart PC sound card is used as data collection plate. Keywords: data collection; multichannel; sound card; ADC; signal processing |
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Economics | |
Article describes possibilities of application of model of the expert knowledge presented in the form of decision trees, for formation of scenary parameters of a simulation model on an example of formation of the Investment program of the enterprise. Keywords: Data-mining, decision tree, system dynamics, information-analytical systems, automation, investment program. |
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In article problems necessary for working out of methods of automation of the organization of pilot production at manufacturing of control systems by the flying machine with use of modern information systems are considered. Introduction of new methods of information support of pilot production of defensive production of aviation instrument making, as factor of increase of efficiency of the organization of manufacture is considered. Keywords: Aviation instrument making; information systems; aviabuilding manufacture, industry |
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The article deals with the main factors and their elements which substantially influence the development of civil aviation aircraft in the world. The article considers new technologies which can be used for civil aircraft production. Analysis of various types of production structures dealing with aviation aircraft is presented. The article considers the main trends of development of Russian aircraft industry from the point of view of increasing its competitiveness in the world market. Keywords: aviation industry, aviation aircraft and equipment, technologies, competitiveness, effectiveness |