Категория: Aeronautics

Preliminary assessment of tracking the autopilot signals by the active controls on a civil aircraft

Posted on by

Savel’ev A. S.

Neretin E. S.

The main purpose of civil aviation is to provide economical, reliable and safe flying. The integrated (fly-by-wire) control system and autopilot system are among the most important aircraft systems. The fly-by-wire control system includes, among other things, controls in the cockpit – yokes (Boeing) and side sticks (Airbus, Irkut, Sukhoi). The side sticks are nowadays a priority in cockpit controls development due to increase of cost-effectiveness compared to the yokes. The rigidly connected yokes provide force feedback for the pilots both in automatic and in manual control modes.   When using the side sticks the pilot has no force feedback because there are no mechanical connections. This has a negative influence on flight safety.  To solve the problem active side sticks are being developed and implemented nowadays. The active side sticks are not certified for any large civil airplanes. The aim of the paper is to give a preliminary assessment of safety of tracking the autopilot signals by the active stick in accordance with   SAE ARP 4761 and SAE ARP 4764A recommendations.

Key words: active controls, control systems, flight safety, fault tree analysis, assessment of functional hazards.

Download article in PDF 234.2 kB

Circulation-vortex method of activating the wing thrust over the underlying surface

Posted on by

UDK 629.735.33.015 BBK 39.15

Kirenchev A. G.

Danilenko N. V.

The article deals with the issue of possible vortex activation of the working process of the wing thrust over the underlying surface. The useful effect of this working process can manifest itself in reducing the aircraft take-off and landing roll in the field of wing vortex interference with the airfield ground. The area of practical use could cover the lifting surfaces of hydrofoil crafts, ram-wing crafts and similar vehicles at low flight altitudes. The vortex activation of the wing thrust is based on the professor N.Ye.Zhukovskiy’s theorem about the wing lift and the mirror effect of the underlying surface proposed by Prandtl. The authors defined the physical and kinematic essence of interference of a linear vortex with a flat underlying surface.  The effect of that kind of vortex interference is represented due to comparison of auto-travel of vortex smoke rings having a different diameter and generated by an identical force pulse. The authors stated the fact of force interaction between a vortex ring and a hard flat wall which forms the basis of the method of vortex activation of the wing thrust capable of reducing the drag. As an object of theoretical research the linear infinitely long vortex of intensity Г = 2p  allowing the mathematical expression of Biot-Savart law to be reduced to the function of vortex velocity св = f (1/(2h)). The kinematic vortex characteristic is represented as a dependence of travel speed on the height of its position above the screen. The article identifies the main consequences of vortex and screen interference and areas of their application.

Key words: thrust, circulation of velocity Г, vortex interference, flat screen, vortex travel, vortex characteristic.

Download article in PDF 452.4 kB

Automation of verifying the electronic display systems of modern and advanced objects of civil aviation

Posted on by

UDK 681.518.3 BBK 39.56

Mamkin E. M.

Krytsin A. V.

Ilyashenko D. M.

Dyachenko S. A.

Neretin E. S.

The authors analyzed the existing means of automation of verifying the software of aircraft onboard equipment. As the result they developed a software application which automates verifying the electronic display systems of modern and advanced civil airplanes as well as a testing technique for its use. The proposed solution allows reducing time and financial costs of system testing.

Key words: civil airplane, avionics, software, verification, image recognition, neural network.

Download article in PDF  270.4 kB

Architecture of the head-up display system for advanced civil airplanes

Posted on by

UDK 681.518.3 BBK 39.56

Dyachenko S. A.

Chufirin V. A.

Neretin E. S.

The paper presents the analysis of design principles for avionic complexes as well as for modern systems of indication in the cockpit. The authors developed the architecture of the head-up display system for advanced civil transport airplanes based on the concept of integrated module avionics. The applied approach allows shortening the time spent for development, tests and certification of an airplane as well as reducing the cost of aircraft operation and its weight and size.   

Key words: civil airplane, integrated module avionics, information presentation systems, systems of technical imaging, head-up display.

Download article in PDF 245.9 kB

The assessment of positioning error characteristics of combined GLONASS/GPS receivers

Posted on by

UDK 621.391:621.396 BBK 39.57-5 S66

Skrypnik O. N.

Arefyev R. O.

Arefyeva (Astrakhanceva) N. G.

The Global Navigation Satellite Systems `(GNSS) such as GLONASS (Russia) and GPS (the USA) systems find wide application in different fields including aviation. The growing demands of different users’ groups for accuracy and reliability of positioning can be met by solving a navigational problem with the use of all visible satellites which belong to different systems. This function was implemented in combined GNSS receivers, the research of performance features and positioning error characteristics of combined GLONASS/GPS receivers under different conditions of use and in different operational modes being relevant. The paper contains the results of natural experiments for investigation of positioning accuracy characteristics carried out with Geos-1M receiver. The experiments were performed in urban settings and in open terrain, in GLONASS and GPS operation modes of the receiver as well as in GLONASS/GPS combined mode. The experimental results were analyzed with the help of special software and algorithms of statistical manipulation. The obtained results allow assessing the main statistical characteristics of positioning errors and operational efficiency of the combined GNSS receiver under different conditions and in different operational modes. It can be used in practice for selecting a more efficient operational mode of the combined receiver for given conditions as well as for validating mathematical models of the positioning errors of SNS receivers.

Keywords: global navigation satellite system, GNSS, combined GNSS receiver, positioning accuracy.

*This work was supported by the Russian Foundation for Basic Research (Grant No. 19-08-00010 A).

Download article in PDF 545.4 kB

Technology of manufacturing some elements of a combustion chamber with a lateral system of reverse current area formation

Posted on by

UDK 621.45.022 BBK 39.55

Skorobogatov S. V.

Isaev A. I.

With each passing year, the operational requirements for the aircraft power plants are getting stricter and stricter. The combustion chamber as one of the main parts of an aircraft engine determines the indicators of its efficiency, reliability and environmental compatibility. The indicators can be improved due to taking into account the operational requirements at the stage of designing a combustion chamber.

As the concept of a combustion chamber with a lateral system of reverse current area formation implies presence of a number of thin-walled elements as well as double-curved surfaces, designing a chamber of such construction is a complex engineering problem.

The article describes a technology of manufacturing a combustion chamber of the desired design on an example of experimental model for a chamber stand.

Key words: combustion chamber, aircraft gas-turbine engine, operational features, technology of manufacturing, combustion process.

Download article in PDF 1.4 MB

Peculiarities of vortex interference of air intakes of gas-turbine power plants with the underlying surface

Posted on by

UDK 629.7.036.3 BBK 39.15

Kirenchev A. G.

Danilenko N. V.

The article considers the basic problems of vortex formation phenomenon and its natural and technogenic vortices. A new definition of vortex formation based on the physical essence of the working process is given. The mathematical foundation of the working process of vortex formation is presented with the use of Professor N. E. Zhukovsky’s theorem about the lifting force of the wing, as well as the equation for conservation of the gas movement energy and the Stokes theorem about the equality of the vortex tension and velocity circulation. Due to the analysis of the energy conservation equation the main factors of generation and accumulation of natural and technogenic vortices are revealed. The issue of the determining role of the underlying surface for forming effluent vortices of air intakes of aircraft gas-turbine propulsion systems is investigated. Influence of other external factors on the formation of technogenic vortices is noted. Classification of technogenic vortex formation and its vortices by the essence of the working process is given.

Keywords: vortex formation, technogenic vortices, vortex interference, the role of the underlying surface, gas turbine power plants, mathematical justification of Coriolis force vortices, air intake.

Download article in PDF 1.0 MB

Analysis of diagnostic techniques for aircraft aerometric systems with the use of data recorders

Posted on by

UDK 629.7 BBK 39.56

Shomankov D. A.

Potapov I. A.

Korshak S. A.

The article contains some results of the analysis of diagnostic models and techniques for defining the dynamic errors in indications (measurements) of flight altitude and speed parameters caused by lag (delay) of pressure transmission in the lines of the pitot probe systems. Their essential drawbacks are revealed and the ways of their elimination are defined.

Key words: dynamic error, pneumatic circuit, pressure, temperature, delay, aerodynamic correction, delay coefficient.

Download article in PDF 346.8 kB

Reduction –based increase of robustness of a neural-net model of gas-turbine engine monitoring

Posted on by

UDK 621.438, 004.855 BBK З363.3, 32.813, 22.18

Novikova S. V.

Kremleva J. Sh.

The article presents a technique of increasing the robustness of a neural-net model of gas-turbine engine monitoring during stand tests due to decreasing the number of insignificant links in the neural network (neural network reduction). The technique is based on converting the problem of neural network learning into that of multi-criteria optimization which includes the error minimization criterion and the criterion of minimizing the absolute values of the weight links of a neural network. The latter requirement leads to reveal of insignificant links which can be deleted without any loss of accuracy. As a result, the ability of the model to summarize increases greatly, robustness increases as well, the calculation error of monitored parameters decreases.

Key words: model robustness, neural networks, stand tests, monitoring of a gas-turbine engine, reduction of a neural network.

Download article in PDF 219.4 kB

A proposal to modernize the SSJ 100 onboard maintenance system

Posted on by

UDK 629.7.05 BBK 39.56

Cavvina A. M.

The need for an onboard maintenance system on modern civil airplanes is caused by the increasing number of flights and the reducing parking period.  The operation speed of an onboard maintenance system greatly influences the efficiency of aircraft operation, the time to reveal and eliminate a failure being considerably reduced. The flight safety increases as well. The economic expenditures of airlines for additional ground service vehicles are reduced.

Key words: onboard maintenance system, maintenance, SSJ 100, Superjet.

Download article in PDF 617.2 kB

« Older Entries Recent Entries »