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

COMPUTER TECHNIQUE

1017
Data transmission systems with a heterogeneous flow of queries of various criticality to the admissible time of stay in the system are considered. The possibilities of increasing the probability of timely and error-free delivery of packets due to their priority redundant service are analyzed. Priority and multiplicity of a reserved request (the number of copies of created queries) is set depending on the allowable waiting time, the backup copies of requests can be placed in queues of different priorities. Multichannel queuing system with the allocation of queues of different priorities is investigated. In the multichannel systems under consideration, all service channels are available for all priority queues. With a redundant service, the request is considered timely and error-free if at least one of its copies is accurately executed for the maximum allowable time. The effectiveness of the discipline of priority maintenance of the non-uniform flow of requests is determined by the probability of timely and error-free execution of all types of requests, with different multiplicities of their reservation and the maximum allowable waiting time. A simulation model for supporting the choice of design solutions for the organization of exchange through redundant channels implemented in the AnyLogic 7 environment is proposed. It is shown that increasing the reservation multiplicity for critical queries with a small load, leads to an increase in the probability of timely error-free servicing of all types of requests, and there is a limit of expediency of their reservation.
ORGANIZATION OF CONTROL OF COMBINATIONAL CIRCUITS BASED ON THE METHOD OF LOGICAL COMPLEMENT TO EQUILIBRIUM 1-OUT-OF-4 CODE Sapozhnikov Valery V., Sapozhnikov Vladimir V., Ephanov Dmitry V., Dmitry V. Pivovarov
1025
A variant of the development of the method of logical complement by the equilibrium code is pro-posed. A method of organization of control of combinational logic devices based on the method of logical complement to the equilibrium 1-out-of-4 code is presented, which does not require additional determination of the values of one of the working functions of the object of diagnosis. The method employs a step-by-step algorithm to determine the control functions, considering the formation of at least once all test combinations for the elements of addition modulo two in the logical complement block and the tester. Uncertainties arising in the process of obtaining the values of control functions allow optimizing the structure of the control logic block and minimizing the complexity of the final device. Complexity of technical implementation of the end device is also affected by the choice of non-convertible function and the sequence of supplementing function definition. Replacing functions in the sequence of supplementing definitions allows to choose the best way to build a control scheme by the index of structural redundancy of the end device. The disadvantage of the considered method is the necessity to ensure the appearance of the required set of test combinations at the inputs of the logic device, which can be difficult with a small number of inputs.
1036
Increase in productivity of industrial control system raises requirements to the accuracy of the digital tracking systems (DWS) of basic and rotary devices. Compensation of a high-speed mistake and mistake on acceleration often appears to requirements of dynamic accuracy is often sufficient for meeting the requirements. In part II, compensation of a high-speed mistake and mistake of acceleration of TsSS modern industrial control system in which rate of calculation of a mismatch can be chosen rather high is considered. At increase in rate of calculation of a mismatch of TsSS of the combined management on properties comes nearer to the continuous watching system of the combined management which parameters are determined. The method of calculation of TsSS of the combined management is proposed. The essence of the method consists in providing the continuous tracking system with management quality indicators which are slightly better than the set in TsSS, and the choice of mismatch calculation period providing the prescribed quality of TsSS management. As a result, it is possible to receive in TsSS of the combined management, a high quality of the free processes as well as of transition processes caused by change of the setting influence.
1045
A procedure of adaptive coding of signals in dynamic systems for subsequent data transfer to another system is presented. An algorithm for the signal quantization level adjusting is proposed based on calculation of moving average norm. A numerical and experimental investigation of the proposed algorithm is carried out, the process of its operation is described. As the encoded signal, the data obtained from a real quadrocopter moving in vertical plane is used. Results of numerical simulation demonstrate the applicability of the proposed algorithm for coding signals in a real dynamic system. The adaptive coding algorithm is implemented in software for use with radio modems for subsequent transfer to a real quadrocopter. The logic of the program and method of formation of information packages based on the results of coding are described. The quality of encoding of harmonic signals of different frequencies is numerically investigated; the influence of the rate of change of signals on the quality of the received signal is characterized by the standard deviation. Recommendations are given to improve the quality of coding with a known character of the original signal.

ELECTRONIC AND ELECTROMAGNETIC DEVICES

FEATURES OF USING MULTILEVEL INVERTERS IN PRECISION SERVO SYSTEMS Tomasov Valentine S, Usoltsev Aleksander A., Vertegel Denis A.
1052
The expediency of application of multilevel inverters in systems of the precision servo drive, caused by the increased requirements to reliability, accuracy, a range of regulation of speed and the moment, and energy efficiency of similar systems is considered. The advantages and disadvantages of the main topolo-gies of multilevel inverters are studied, results of mathematical modeling obtained in MatLab/Simulink are analyzed. To compare the harmonic composition of the current formed by different transducer topologies, it is proposed to use the coefficient of variation of the generalized stator current vector. The use of multi-level topologies of voltage inverters allows to expand the range of output voltage regulation, to reduce the influence of dead time, to use keys designed for lower operating voltage, as well as to improve the harmonic composition of the generated current, which directly affects the reduction of electromagnetic moment pulsations. Based on the research results, it is concluded that the use of multi-level inverters in precision electric drive systems has advantages over the use of traditional two-level topologies.
ULTRASONIC INSPECTION OF METAL STRUCTURES USING PHASED ELECTROMAGNETIC-ACOUSTIC ANTENNA ARRAY Bazylev Dmitry N, Vitaliy A. Romanovich, Sergey N. Somov, Pyrkin Anton Alexandrovich
1060
The task of pipeline diagnosing with the use of a phased antenna array (FAA) on an electromag-netic-acoustic converter (EMAC) is considered. A new algorithm for phased EMAC arrays is proposed; the algorithm provides improved accuracy characteristics and a faster scanning of a test object than the classical diagnostic method with FAA. The efficiency and performance of the developed scanning algorithm is studied experimentally with the help of the EMAC-FAA prototype and a test sample. Comparison of the new algorithm with the classical one on the base of the experimental results demonstrates that the proposed scanning solution allows to reduce the effect of crosstalk significantly and to increase the signal-to-noise ratio in the distributions of the echo signal amplitudes.
1067
The modern level of development of technique even more expanded a scope of electrical devices with levitation elements, used for exact stabilizing of an alternating current in adjustable loadings, automatic monitoring of not electrical parameters of technological processes, etc. Analytical expressions for parameter optimization and analysis are derived. The presence of dimensionless quantities simplifies the calculation and construction of relationships between the parameters in an explicit form. Based on the obtained relations, recommendations to design of various electric devices with levitation elements are developed.

OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

1072
In order to increase the information content of an image at low light conditions with an excessive number of strobing pulses, when the total exposure time is not enough to eliminate the deficiency, it is proposed to obtain two separate frames - in passive (normal) and AI-mode of operation, and then sum-marize them pixel-by-pixel. A control mode of the CCD photodetector with line transfer is developed, which allows to increase the exposure time at low light conditions in the active-pulse observation system without the use of an optical-electronic converter.
GRAPHIC COMPOSING OF OPTICAL SYSTEMS Ivanov Aleхandеr N. , Fedorov Yury V.
1077
The possibility of using graphic methods at the stage of analysis and synthesis of optical systems based on a rational combination of basic optical elements: aplanatic lenses, mirrors and concentric systems is considered. The harmonious system of optical schemes composition for various purposes, proposed by M. M. Rusinov, is supplemented using graphic editors. Modern graphic editors, e.g. AUTOCAD, VISIO, KOMPAS, allow to make constructions visually and with high accuracy and as a result to minimize volume of calculations at creation of new optical system. Computational work is reduced to the verification calculation and, if necessary, to a small revision of the system, which may well be performed in a graphical editor.

SCIENTIFIC AND PRACTICAL DEVELOPMENTS

TITANIUM SURFACE ABLATION BY DOUBLE NANOSECOND PULSES Mikhail V. Lukiantcev, Andrey A. Samokhvalov
1083
The effect of double nanosecond laser pulses on the titanium surface and the changes in the morphology of ablative catheters caused by them are studied. The considered mode of dual nanosecond pulses allows more efficient use of laser energy for the problems of microrelief formation in comparison with the mode of mono-pulse action due to the separation of the "excess" power density by the time delay exceeding the lifetime of the laser plasma. It is shown that the variation of the time parameters of the double pulses leads to an increase in the depth of the removed layer by about 1.5 times, a twofold increase in the aspect ratio, as well as a decrease in the amount of the liquid phase of the material emitted by the recoil pressure. A complex two-level microstructure of craters is found to be formed in the mode of dual nanosecond pulses. The obtained crater structures in the mode of double nanosecond pulses can be used to change the tribological properties of the metal surface and to create functional micro-reliefs.
APPLICATION OF VIRTUAL INFRASTRUCTURE COMPONENTS IN CONSTRUCTION OF A LABORATORY COMPLEX IN AN EDUCATIONAL INSTITUTION Alexander Yu. Filimonov, Denis A. Medvedev, Alina S. Klimova, Artyom A. Muravyov
1092
It is noted that construction and support of laboratory facilities in an educational institution is a complex task, the solution of which requires significant resources. It is shown how the use of virtualization technologies of network infrastructure components allows more complete use of the available equipment of the laboratory complex, to intensify the learning process and to instill in students the practical skills of building modern data transmission systems. The approach is used to modernize the laboratory complex of the educational institution by distributing the computing resources of routers and the server of the real carrier network between virtual routers and virtual workstations, and communication resources of physical channels between the corresponding virtual channels. To simulate workstations in the laboratory complex, a typical workstation virtualization solution (Virtual Desktop Infrastructure, VDI) is used.