ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
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Summaries of the issue

INFORMATION TECHNOLOGIES AND SYSTEMS, COMPUTER TECHNIQUE

687
Methods of synthesis of fault-tolerant discrete devices and systems are investigated. A block dia-gram of signal correction based on the use of double modular redundancy with control of calculations by a preselected feature is proposed. Three options for the implementation of this structure are analyzed. The first structure is based on the control of computations by a copy of the original device by code with repetition, which in fact implies the use of a computation control scheme by the duplication method. The second structure is the control of computations based on a parity code. In the third structure, the control scheme uses a special code with summation of the coefficients of weighted transitions from category to category in the information vector, which makes it possible to construct a control scheme that is simpler than with duplication. Results of experiments on evaluating the efficiency and complexity of the tech-nical implementation of each of the proposed structures with the use of control combinational circuits LGSynth’89 and MCNC Benchmarks are presented. The proposed structures of signal correction circuits based on double modular redundancy are built from standard blocks, which allows them to be widely used for synthesis of fault-tolerant discrete devices.
702
The problem of reducing information redundancy when exchanging data in networks with a long range and low power consumption is analyzed. The approach under consideration is based on reduction of the size of additional service fields that determines the information packet source and its number in the single message. To increase the entropy of these additional service fields, it is proposed to write in them a hash formed from data from other information packets of the source and the source unique identifier. A formalized algorithm for analyzing incoming information packets by the receiver which allows deter-mining the source of the information packet is described. The problem of an error in determining the se-quence number of a fragment in a single message is formulated. Based on the mathematical apparatus of the probability theory, numerical characteristics of such type of error are derived, and its influence on the information redundancy is estimated. Dependencies between the additional hash field length and number of the transmitted message fragments are presented, and the range of the values providing the minimum information redundancy is determined.

INSTRUMENTS AND SYSTEMS OF AUTOMATIC CONTROL

MEASURING THE DERIVATIVE OF CURRENT USING A DELTA-SIGMA MODULATOR FOR SENSORLESS CONTROL OF A TRACTION ELECTRIC DRIVE Alecksey S. Anuchin , Evgeny O. Stolyarov, Galina L. Demidova, Yuriy Vagapov, Alexander A. Zharkov, Dimid K. Surnin
711
A method of direct measurement of the derivative of current necessary to determine the induct-ances in electric motors for reliable and efficient operation of sensorless control in AC electric drives is considered. The method is based on measuring the voltage drop across a calibrated inductance installed directly in the converter power circuit. To improve the method accuracy and reduce the effects of transi-ents and interference, a delta-sigma modulator is used to measure the voltage drop. Experimental re-sults obtained for three different inductive measuring shunts are presented.
711

OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

GEOMETRY CONTROL SYSTEM FOR AXISYMMETRIC PRODUCTS WITH ANGLE MIRROR CONVERTER Alexander A. Kulchitsky, Anatoly I. Potapov, Boikov Vladimir I. , Vitaly A. Tarala, Andrey G. Smirnov
720
An optical system for controlling the shape and geometry defects of axisymmetric products using one digital camera is considered. To obtain the possibility of a complete view of the object surface in the control zone, an angular mirror converter is used. The advantages and disadvantages of the proposed layout are discussed, and the area of its application is determined. The diagram and the calculated ratios of the control system parameters are presented, and recommendations for their choice are given.
727
The problem of designing optical systems of circular radiation with several multidirectional sources for devices of wireless Li-Fi communication between vehicles is considered. A modification of the ray mapping method for the problem of designing optical elements of a Li-Fi module is proposed by introducing an integral source model. The results of calculations and virtual prototyping of devices designed using the proposed method are presented.

HEAT REGIMES AND RELIABILITY OF INSTRUMENTS AND SYSTEMS

LASER LOCAL HEATING SYSTEM FOR THERMAL VACUUM TESTING OF SPACECRAFT Anton A. Kishalov, Alexander E. Puysha, Vladimir М. Zhurba, Anatoly G. Popov, Alexander К. Sharov, Аnton V. Khakhlenkov
739
A new light source based on itterbium fiber laser is proposed for spacecraft thermal vacuum tests. Local heating laser system using as test equipment and consisting of 20 laser channels is devel-oped and manufactured. Each of the channels creates a quasi-uniform circular laser spot with a diame-ter of 50 to 250 mm and a power density of up to 55,000 W / m2 on the test object surface.

INSTRUMENT-MAKING TECHNOLOGY

749
A technique of fuzzy inference of single quality criteria is presented. The technique is based on ad-ditional data and is using a model for determining the significance of information sources that satisfy a two-level model for assessing the quality of instrument-making products. The issues of assessing the quality level are considered, target functions of quality are proposed, areas of definition for each level of optimization are established, and a method for quantitative identification of single quality criteria is devel-oped. Several ways to improve the developed method are proposed.

SCIENTIFIC AND PRACTICAL DEVELOPMENTS

756
The reasons for complication of the design, increase in weight and cost of traditional systems for measuring aircraft air signals based on aerometric, aerodynamic and vane methods for measuring pa-rameters of incoming air flow are considered. These reasons are reported to limit the scope of such sys-tems and determine the relevance of the development of an air signal system based on the vortex meth-od using one integrated flow sensor. Analytical models for signals in the measuring channels of an orig-inal system of subsonic aircraft air flow signals, based on a vortex sensor of the aerodynamic angle and air speed, are presented. The instrumental and methodological errors of the measuring channels of the air signal system based on the vortex method are analyzed.
763
A device for measuring micro-concentrations of sulfur-containing substances in gaseous media is developed. The detector is a photoionization generator with a thermo-isolated cylinder. The detector de-sign and principle of operation are described, the possibility of its application in a measuring system in-tended to determine micro-concentrations of sulfur-containing substances in exhaled gas is considered. The measuring system schematic is given, its elements and practical operation are described. The sys-tem efficiency in determining sulfur-containing substances concentrations in the range of 0—20 ppb is confirmed experimentally.

BRIEF NOTES

CYLINDRICAL GEARS WITH TAPERED TOOTHED RIMS Medunetskiy Viktor M. , Vladimir A. Zinkov
769
To reduce the clearance in the gearing area of cylindrical involute gears, it is proposed to use tapered gears. Features of this type of gearing and assembly of a gear transmission are given. Gears are proposed to be made by casting in silicone molds and by 3D printing.