Vol 30, No 1 (2022)

Informatics, Computer Science and Control

Analytical approximation and numerical simulation of liquidus for non-equilibrium multi-component eutectic systems

Afanaseva O.S., Afanaseva E.A., Egorova G.F.


In the first part of the article, the methods of analytic approximation of melting curves for two-component systems and their visualization by means of computer graphics are considered. For two-component systems, a method is proposed for the approximate construction of a melting curve, based on their by approximation of polynomials of the first and second degree. The diagrams obtained by solving the Schroeder Le Chatelier system and the liquidus curves constructed on the basis of their approximation by polynomials are compared. The value of the maximum deviation of these approximations from each other is given. The errors of the diagrams of two systems are considered separately: Ba(ClO4)2 – KClO4 and BaF2 – BaSO4, obtained experimentally and constructed using a system of Schroeder Le Chatelier equations and their approximation by polynomials of the first and second degree. In the second part of the article, a method is proposed to construct crystallization surfaces for three-component systems based on the approximate formulas for calculation eutectic characteristics of the two-component and three-component systems, and the linear approximations of the three-component systems isotherms. Based on the proposed approximation procedure, a method for calculating the composition and temperature of eutectic for two-component systems, and the construction of three-component system isotherms in the Delphi visual programming environment with the user interface is created. The table of errors of the eutectic characteristics calculations for three-component systems is given. The results of visualization of numerical simulation of liquidus surfaces for three-component eutectic systems and their comparison with experimentally obtained samples of crystallization surfaces for two systems: Ba(ClO4)2 – KClO4 and BaF2 – BaSO2 are presented.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):6-19
pages 6-19 views

Development of models, methods and tools for creating a digital platform for agreed planning of heterogeneous group of small space satellites for remote earth sensing

Galuzin V.A.


The paper describes a development of models, methods and tools for creating a digital platform for coordinated planning of heterogeneous orbital constellations for Earth remote sensing, which can include from several dozens to hundreds of small satellites. These orbital constellations are created in response to the massive increase in the load on currently operating systems. New systems, in comparison with traditional single satellite, impose much more tough requirements on methods and means of planning, and only a few of the existing solutions can at least partially correspond to them. Thus, there is a need to develop new planning approaches that take into account the domain semantics more deeply. As one of such approaches, the paper presents expanded application of multi-agent technology. The essence of this approach lies in numerous negotiations between agents of imaging applications through mutual compromises and concessions. And the desired efficiency is achieved by searching for the global optimum for each application and using this information in a targeted search for a general solution for the entire system. The paper provides a problem statement of planning the operation of an orbital constellation for Earth remote sensing. Furthermore, it describes the developed method, which makes it possible to process applications for imaging observation objects in real time. The paper also presents results of experimental studies that demonstrate efficiency of the developed multi-agent method in solving this problem versus traditional approaches. The architecture of the developed system is proposed, describing the functions of the main modules and screens. The obtained results and prospects for further development and application of the developed approach are discussed both for solving complex problems of adaptive control of small satellite constellations in mission control centers on Earth, and for creating a distributed space system "Swarm of satellites" for operation in open space.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):20-45
pages 20-45 views

Intelligent system of adaptation typical laws automatic regulation with the function of identification structure and parameters object

Lysenko D.S.


The structure of an intelligent system for adapting typical automatic control laws with the function of identifying the structure and parameters of an object has been developed and described. The developed system solves a complex of interrelated tasks: identification of the structure and parameters of an object, calculation and selection of the controller type, determination of parametric disturbances in a closed control loop. The intelligent system consists of three circuits: the identification circuit, the ACS design circuit, and the executive circuit. The tasks of the identification circuit include: identification of the structure and parameters of the object by observing the time characteristic of the object with a step action at the input; determination of the presence of a parametric disturbance by the method of comparative assessment of transient processes of the reference model and the real control object. According to the results of identifying the structure and parameters of the object, the controller is designed - the calculation of parameters and the choice of the type of controller. The executive circuit is represented by a closed control system. Neural networks were chosen as a tool for implementing the identification subsystem and the regulator design subsystem. As a prototype of the control object, typical dynamic links and their connections were chosen. The article contains: description of the structure of the intelligent system of adaptation of typical automatic control laws; description of subsystems for identifying and designing the regulator, structural and graphical diagrams, simulation results.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):46-62
pages 46-62 views

Deep neural network for diagnostics of railway track components

Orlov S.P., Efimushkin N.A., Efimushkina N.V.


The problem of increasing the speed of railway transportation and ensuring reliability is associated with constant monitoring of the condition of the railway tracks. The modern track measuring cars are equipped with video cameras and computer equipment for processing the received information. However, manual processing of data by operators in real-time is not possible. The article proposes a deep convolutional neural network for automatically recognizing and classifying defects in rail joints on rail track images. The rail video observation forms the image array during the passage of the track recording car. The formation of classes of rail joints is described. Regular rail joints with connectors, insulating joints, and welded joints are considered. Additional classes are identified, corresponding to various anomalous configurations of rail joints in the images. A modified structure of a pre-trained deep convolutional network is constructed. When preparing training samples, the actual images of rail joints were supplemented with artificial images obtained by affine transformations. The process of training and testing the classifier based on the developed convolutional network is described. The Transfer Learning is used to train the neural network. As a result of the experiments, the accuracy of classifying rail joints and detecting defects was at least 96%.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):63-74
pages 63-74 views

Instrumentation, Metrology and Informative-measurings devices and systems

Smoothing of chromatographic signals by their approximation in the basis of Chebyshev-Hermite functions

Bochkarev A.V., Sayfullin R.T.


The paper deals with assessing the scope of the approximation algorithm for smoothing chromatographic signals. The algorithm is based on Chebyshev-Hermite functions. For approximation, an algorithm is used that implies the calculation of the shift and scale factors for the basis functions, as well as the division of the signal into fragments. The smoothing error of the model signal is considered when it is approximated in the selected basis in comparison with the digital moving average filter. The error of smoothing the derivative of the signal and the position on the derivative of extremums is also investigated, a comparison is made, as in the previous case, with a digital moving average filter. As part of an experimental study, the nine most characteristic chromatographic peaks extracted from real chromatograms are processed in the work. To assess the quality of smoothing, the standard deviation of the noise and the residual are compared, and the distribution law of the residual is determined. According to the results of the study, restrictions are set on the maximum allowable value of the asymmetry coefficient of the processed chromatographic peaks. Thanks to the use of the chosen approximation approach, it is possible to solve the problem of smoothing chromatographic signals without attenuating the useful component. The computer algebra system Wolfram Mathematica 11.3 was used for calculations and graphical presentation of the simulation results.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):75-89
pages 75-89 views

Electrical Engineering

Development and research of induction heating system in technological complexes of oil transportation

Danilushkin A.I., Danilushkin V.A.


The problem of development and research of an induction system for heating viscous non-conductive liquids during transportation through pipelines is considered. A specific feature of the research object is the combination of the processes of heating a laminar fluid flow in a cylindrical inductor and mixing in a three-phase inductor - mixer. Research of interrelated electromagnetic, thermal and electromechanical processes in heating and stirring systems has been carried out. The results of a numerical calculation of electromagnetic and thermal fields and the electromagnetic moment of rotation of the rotor in a heated liquid are presented. A relationship has been established between the thermal power released in the elements of the system and the power used to rotate the rotor. The electromechanical (control) characteristics of the induction mixer are given. It is shown that with an appropriate choice of design and operating parameters of the induction system, it is possible to find the required ratio between the thermal power released in the elements of the system and the power used to stir the liquid. The results of the research are intended to solve the problems of designing the design of induction systems for heating viscous liquids and effective control of the heating process.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):90-105
pages 90-105 views

Accounting for wire saggingоn span of 220 kV OHL whendetermining current, induced in ground wire by phase current magnetic fields

Krotkov E.A., Bezmenova N.V., Shchobak A.A.


Overhead ground-wire cable (GW) is more prone to ice formation compared to 220 kV overhead lines. Ice-melting methods for GW using special power source have certain engineering constraints and required is connection of overhead line. Preventive heating of GW to above-zero temperature is an equivalent method to ice-melting. Preventive heating shall be provided by induction from electromagnetic field (EMF) of 220 kV overhead lines while in service. Induction methods of 220 kV OHL GW heating have been summarized and briefly described. Mathematical models of GW inductive heating do not consider the influence of wire and GW saggingon EMF parameters and equivalent circuit “ground wire-earth”. Therefore, sufficient mathematical model is required to use induction method of GW heating at 220 kV OHL segment. We propose induction heating for GW of double-circuit 220 kV OHL inclosed circuit “ground wire-additional conductor” top reventice formation. Mathematical model have been developed to calculate current, induced in circuit “ground wire-additional conductor” by magnetic fields of 220 kV OHL current while in service. Influence of wire and GW saggingon EMF parameters and equivalent circuit “ground wire-additional conductor” has been estimated. Due to mathematical model we could estimate induced current to prevent ice formation on GW of double-circuit 220 kV OHL while in service. Closed circuit “ground wire-additional conductor” is recommended for practical use, with capacitor loop included into circuit, its capacitance to be determined based on voltage resonance conditions.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):106-117
pages 106-117 views

Determinationturnsamountandcoils scheme connection of the secondary winding a three-phase-multiphase phases number transformer converter

Moskalev Y.V.


The article lists various technical devices and systems that require transformer converters of the number of phases. Increasing the number of phases can significantly improve the performance and characteristics of such devices and systems. An approach has been developed to determine the minimum coils number of the secondary winding of a three-phase-multiphase transformer converter, each phase of the secondary winding of which consists of three coils connected in series, one placed on each of the three core rods. The number of turns can be calculated for the secondary winding, the number of phases of which is more than two. An example is considered for determining the number of turns of the coils of the secondary winding of a three-phase-five-phase transformer converter. The diagram of the connection of the secondary winding of such a device is given, the calculation of the total power of the coils of the secondary winding for a given multiphase load connected as a multipath star is performed. A simulation model of a three-phase-five-phase converter has been compiled in the Matlab Simulink simulation environment. The necessary circuit for connecting the windings is implemented using single-phase transformers with different transformation coefficients. Symmetrical five-phase voltage system is obtained as the output data of the model. For a different number of phases of the secondary winding, the values of the coefficient are calculated, which allows us to estimate the number of turns required to form one phase of the secondary winding of the converter. Using this coefficient, the comparison of the number of turns of the coils of the secondary winding of the device with a different number of phases was performed.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):118-129
pages 118-129 views

Influence of operating dc network parameters on the operation insulation monitoring system on the ground

Skripachev M.O., Vedernikov A.S.


Direct operating current system is a set of electrical devices and appliances, including power sources required for the functioning of the main technological complexes of enterprises. The features of direct current systems are a significant spatial distribution, susceptibility to strong electromagnetic interference and noise. A frequent fault in DC operating current systems isolated from the ground is the damage of the insulation of one pole to ground. This fault is not accompanied by large currents, but can cause false operation of the electrical system. In this paper we consider the method of searching for the faulty section, and analyze the occurrence of interference in the search system. The improved search system based on the external reference voltage superimposition method has confirmed its performance in real objects.

Vestnik of Samara State Technical University. Technical Sciences Series. 2022;30(1):130-142
pages 130-142 views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies