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

INFORMATION TECHNOLOGIES AND SYSTEMS, COMPUTING TECHNIQUE

583
Some problems of constructing automation and computer technology devices with self-checking structures are discussed. The possibility of developing a modification of the well-known logical com-plement method for the purposes in question is considered. The essence of the method consists in ini-tial transformation of the source device operating functions into functions of a special type and subse-quent control of them according to selected diagnostic criteria. To implement the method, a logical complement block is used, formed by a cascade of two-input adders modulo two. An approach based on a hybrid method of organizing control is proposed: initially, the signals coming from several outputs of the source device are compressed, and then the compressed signals are controlled by the logical complement method. It is shown that the approach allows to reduce the final device structural redun-dancy by reducing the number of control sub-circuits. The effectiveness of the new approach as applied to organization of self-checking devices is confirmed by an example which demonstrate the possibility to build a device not only with a structural redundancy lower than with duplication, but also comparable and even less than with control by parity.

INSTRUMENTS AND SYSTEMS OF AUTOMATIC CONTROL

PRECISION ELECTRIC DRIVE BASED ON THE MULTI-PHASE INVERTER WITH SPACE-VECTOR MODULATION Denis A. Vertegel , Aleksander A. Usoltsev, Valentin S. Tomasov
600
The problem of improving precision electric drives quality by minimization of the stator current pulsations generated by frequency inverter is discussed. The problem can be solved by using multi-phase inverters, as well as by improving the control algorithms. The influence of space-vector modula-tion algorithm on pulsations of stator current generated by a five-phase voltage inverter for various se-quences of basic vectors formation is considered. Changing the sequence of base vectors is shown to have a significant effect on the level of generated stator current pulsations. Two possible approaches to implementation of the space-vector modulation in the five-phase electric drives are presented, and com-parative analysis of the approaches with and without considering the dead time, is carried out. Results of modeling are presented, confirming that minimizing the number of commutations per modulation period with deep control of the electric drive speed has a significant impact not only on the level of the stator current pulsations, but also on the compensation of the current vector in the second plane of the base vectors, which can cause overheating and subsequent failure of the electric motor.
611
The dynamics of the pendulum sensitive element of the railway track level detector mounted on a moving platform is considered. A differential equation is derived to describe the element dynamics un-der the effect of the track roughness as well as vibration, expressions for initial conditions are defined. An analytical solution is obtained for the equation of the pendulum dynamics in the case of one-dimensional vibrations along the horizontal axis. The equation for two-dimensional vibrations is solved numerically. Presented results of analytical calculations and simulation using the finite element method confirm the developed model adequacy.
620
A block diagram of a digital angle converter with the ability to correct single errors is proposed. Implementation of the correction ability is achieved by application of recursive code scales with one in-formation code track in them. With such scales it is possible to generate correction codes read from them with a minimum code distance dmin = 3 by introduction of additional reading elements only (without the use of additional control code tracks).
EVALUATION OF LOW-FREQUENCY NOISE RELATIONSHIP IN MULTICHANNEL REGISTRATION OF ECG SIGNAL Kremlev Artem Sergeevich, Zimenko Konstantin A., Yeldos А. Аltay
626
A method for processing multichannel recording of ECG to isolate low-frequency interference in various leads is presented. The method is based on polynomial Newton filtering of high frequencies. The efficiency of the proposed method is analyzed, and a comparative analysis of its effectiveness relative to the known approaches is carried out based on quantitative indicators. Using the developed method, low-frequency interference was isolated from a noisy multi-channel recording. Based on the selected samples, a high correlation between low-frequency interference in various and adjacent leads of the electrocardiogram is established.
634
The influence of errors of pressure sensors and accelerometers on accuracy of indirect meas-urement of aircraft aerodynamic angles is studied. Total error of indirect calculation of glide angle is de-termined analytically using the М101Т aircraft as an example. Graphical dependences of angle of attack measuring error on errors of pressure sensors and accelerometers as well as inaccuracies in the indi-rect calculation of design parameters obtained by model study of the TU-104 aircraft in various flight modes are presented. As the design data, aerodynamic characteristics of the aircraft and calibration characteristics of the propulsion system are used.

OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

640
The problem of designing optical system with free-form elements is considered. A modification of the light energy mapping method for design of optical system for aviation obstruction lights of low inten-sity is proposed. An algorithm for calculating optical elements for such devices is described. Results of calculation and virtual prototyping of the device, carried out according to the proposed method, are pre-sented.

INSTRUMENT-MAKING TECHNOLOGY

650
A method for quantitative identification of single criteria of instrument-making products quality for a two-level model of the products assessment is developed. Problems of quality assessment are con-sidered, target quality functions are proposed, areas of definition for each level of optimization are estab-lished.

SCIENTIFIC AND PRACTICAL DEVELOPMENTS

657
A statistical method for analyzing the temperature stability of electronic devices is considered. It is shown that, on the basis of a factorial experiment, it is possible to obtain an equation of temperature er-ror, in which a functional relationship is established between factors (temperature of electrical radio products) and the output parameter of an electronic device. Since under the conditions of the spatial structure of volumetric integrated circuits, the unification of electrical and radio products is possible not only in a plane, but also at multiple levels, the concept of “volumetric local group” is introduced. Design of such a group is demonstrated to necessitate a preliminary determination of temperature distribution for the volumetric integrated circuit spatial structure. Simulation of temperature field distribution is carried out using the finite element method currently recognized as the most effective numerical method for solving the differential equation of thermal conductivity. Results of temperature stability modeling for a pulsed power amplifier designed as a three-layer structure of a volumetric integral circuit are presented.
DETERMINATION OF WHEAT VITREOSITY WITH MACHINE VISION IN THE NEAR IR WAVELENGTH RANGE Dmitrii E. Troshkin , Gorbunova Elena V., Chertov Alexander N., Elena A. Sycheva , Artem A. Alekhin , Igor G. Loskutov, Evgeny V. Zuev
666
The problem of improvement of wheat vitreosity assessment method using technical vision and image processing technologies is considered. Results of experimental studies of seven hard and soft wheat varieties with different color and vitreosity performed with developed hardware and software complex are verified using the standard method of visual inspection of the grain. The grain color is found to have a strong negative effect on vitreosity measurement in the visible wavelength range. This fact casts doubt on the reliability of results obtained using current methods of vitreosity assessment. To eliminate the in-fluence of grain color, vitreosity analysis in the near-infrared wavelength range is proposed. The as-sumption is confirmed a set of experiments: high convergence of results obtained by technical vision and visual analysis is noted. The repeatability of measurement results is shown to be 5 %, and thus meet the State Standard requirements.
673
Mechanical properties and characteristics of acoustic emission of brittle materials under various loading rates are studied. Based on performed theoretical analysis and data obtained during testing of samples of cast iron, coal, and concrete, graphs of the time dependence of stress-strain and acoustic characteristics of the samples are plotted. The mechanical strength and deformation of samples, as well as acoustic emission parameters, are compared with the loading rate. The analysis of mechanical prop-erties and acoustic characteristics of samples provides information that can be used in engineering cal-culations.