Кафедра електроніки, фізики та СМАРТ-систем
Постійне посилання на фондhttps://repository.lntu.edu.ua/handle/123456789/80
Переглянути
12 результатів
Результати пошуку
Item type:Наукова стаття, Modeling the Dynamics of Centerless Mortise Grinding on Rigid Supports(2025) Chalyj, Vasyl; Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Zabolotnyi, OlegThe paper examines the influence of the dynamic parameters of the machine and the geometry of the adjustment of rigid supports on the formation of undulations of the surfaces of roller bearing rings. A complex mathematical model of the machine tool system for centerless mortise grinding was developed, and the influence of the dynamic parameters of the machine tool and the geometry of the setup of rigid supports on the formation of undulations of the processed surfaces was analyzed. The SWaAGL-50 mortise centerless grinding machine’s technological system is presented as a linear mechanical model, and the elastic movements along the ОХ axis are considered. Based on the equations of kinetic and potential energies compiled in the form of Lagrange, the equations of motion of the relevant elements of the technological system were obtained. The formula of the dynamic accuracy function was found, which characterizes the inconsistency of the movement of the grinding wheel and the part.Item type:Наукова стаття, Increasing the Speed and Performance of the Drupal CMS Server for Industrial IoT Technologies(2023) Satsyk, Viktor; Cagáňová, Dagmar; Reshetylo, Oleksandr; Zabolotnyi, Oleg; Tkachuk, AnatoliiIn this paper, the methods of increasing the speed and performance of the Drupal CMS-based server in IIoT technologies were analyzed. Three main load parameters were taken into account: processor time (CPU), level of server RAM usage, and disk memory usage level; on three pages of the WEB site (main, list of blogs, and a page with one blog) and two research methods were applied: generalized and detailed. Based on the results of the analysis of four options for optimizing Drupal CMS for IIoT technologies: basic, using additional installed modules, servers, and configurations, and Drupal Hooks, effective, simple, cost-effective methods were synthesized that guarantee an increase in server speed and productivity. It was found that the optimization of configurations and Drupal Hooks is the most effective since after its implementation, the response of a page with one blog increased by 9.32 requests per second; built-in optimization is extremely simple to implement and inefficient, while server-side optimization is inefficient, most complex and expensive to implement.Item type:Наукова стаття, Improvement of Operational Parameters for High-Precision Tribosystems(2022-09-09) Stelmakh, Alexander; Kostunik, Ruslan; Shymchuk, Sergii; Zaichuk, Natalia; Tkachuk, AnatoliiIn producing plunger pairs of high-pressure fuel pumps, product quality management has a problem of improving their durability and reliability. To improve the performance of products, it is advisable to pay special attention to the tribological characteristics of the friction surfaces that are part of such products, the conditions of their mutual contact, and lubrication. Using a scientific and experimental approach, friction pairs simulating the plunger pairs of high-pressure fuel pumps and aerial gases and diesel fuels used as working lubricants are investigated. The studies take into account the dual nature of friction. The obtained results do not contradict elastohydrodynamic and adhesion-deformation theories. A set of research equipment has been developed, demonstrating the occurrence of secondary currents in the contact zones and the effect of tribocavitation. In the process of friction, microbubbles dissolve in the diffuse contact region. It has been established that with certain types of microgeometric relief, contact load, and a temperature, it is possible to set precision surfaces, which may explain some types of failures of high-pressure fuel pumps and create conditions for expanding the temperature range of these products.Item type:Наукова стаття, The Structure of Automated Control Systems for Precision Machining of Parts Bearing(2022) Trokhymchuk, Ivanna; Svirzhevskyi, Kostiantyn; Tkachuk, Anatolii; Zabolotnyi, Oleg; Zablotskyi, ValentynOne of the ways to improve the quality of bearing parts is the introduction of automatic control systems to improve the technological reliability of machines and increase the accuracy of machining of roller bearing rings. A significant advantage of these systems is that it is possible to compensate for technological factors by cheaper means compared to such as increasing the rigidity of the technological system, processing in modeswith lower productivity, processing using more passes, usingmanualmethods to compensate for wear of cutting tools, maintaining the required rigidity of the machine and the accuracy of its elements through periodic repairs. These methods are associated with either a loss of cyclical productivity or a significant loss of unproductive nature. Therefore, the errors of automated control systems should be considered as processing errors or as a scattering field of the dimensions of parts manufactured on a machine equipped with an automatic control system for precision machining. The share of error of the most automated control system in the total balance of the total size error is quite small and does not exceed 10…20%. The task of improving the accuracy and ensuring stability in technological systems is complex, so it is solved only by a comprehensive method by improving the accuracy of all elements of the technological system. Thus, automated control systems for precision machining of bearing parts is one of the main subsystems of flexible automated production in the concept of Industry 4.0.Item type:Наукова стаття, ЕLECTROMAGNETIC FIELD EQUATIONS IN NONLINEAR ENVIRONMENT(2024) Lyshuk, Viktor; Tkachuk, Anatolii; Zablotskyi, Valentyn; Selepyna, YosypThe paper proposes electromagnetic field equations from the point of view of their adaptation to numerical methods. Maxwell'sequations with partial derivatives are used, written concerning field vectors, which most fully reproduce the picture of physical processes in electrical engineeringdevices. The values of these vectors provide comprehensive information about the field at any spatio-temporal point. The concept of creating mathematical models of electrical devices adequate to physical processes has been developed. Mathematical transformations are carried out according to the rulesof differential calculus. Dynamic processes in the elements of electrotechnical devices were analyzed using the apparatus of mathematical modeling.An algorithm for implementing differential equations with partial derivative numerical methods using computer simulation was implemented. The obtained results made it possible to understand the nature of electromagnetic phenomena in nonlinear media. The paper provides calculations of the field parameters in a flat ferromagnetic plate and the groove of the rotor of an electric machineItem type:Наукова стаття, MODELLING OF DYNAMIC MODES IN A DC MOTOR FOR ELECTRIC VEHICLE(Polytechnika Lubelska, 2026) Lyshuk, Viktor; Tkachuk, Anatolii; Moroz, Serhiy; Yevsiuk, Mykola; Khvyshchun, Mykola; Prystupa, Stanislav; Zablotskyi, ValentynThe paper investigates mathematical models of a DC electric motor with independent excitation for electric vehicles and PWM as a speed control method. Differential equations of electromechanical state are written in normal Cauchy form. This representation simplifies the computational process, since integration is carried out by the explicit numerical method of Runge-Kutta of the fourth order, which is simpler than implicit and more accurate than single-step explicit methods. The symbolic programming language Force 2.0, which is a variant of the Fortran language, is used for modelling. Compared to mathematical packages of simulation modelling, it is convenient in terms of low time costs for compiling the program itself, since the program includes model equations together with initial conditions, a numerical method, and an integration procedure. The developed models take into account electromagnetic couplings of the motor's electrical circuits and make it possible to simulate dynamic operating modes. Such models can be used to analyse the operation of motors both autonomously and as an element of an electromechanical system, including valve converters. The operation and transient modes of a DC motor are simulated, the simulation results are given, and their analysis is presented. The results confirmed the correctness of the chosen approach to modelling and numerical methods, as well as compliance with the classical theory of electric machines.Item type:Наукова стаття, METHOD FOR EVALUATION QUALITY PARAMETERS OF TELECOMMUNICATIONS SERVICES(2022-06-30) Zablotskyi, Valentyn; Selepyna, Yosyp; Lyshuk, Viktor; Yakymchuk, Natalia; Tkachuk, AnatoliiCurrently, cellular networks have become widespread, the operators of which simultaneously use the infrastructure of the second generation GSM networks, DCS to build third generation W-CDMA networks that provide broadband multiple access with code division. At the same time,the problem of providing high-speed Internet connections is exacerbated due to the growing volume of data of diverse types transmitted over the Internet. When testing the entire network coverage area, the total number of voice calls increases, so a method of long-term measurement of bit rate of information transmission via wireless communication channels is proposed, which does not increase the service information in the network.Mathematical modelingof Internettraffic consumption using the proposed measurement method is performed and entropy estimates of information channel bandwidthare given.Item type:Наукова стаття, MONITORING OF LINK-LEVEL CONGESTION IN TELECOMMUNICATION SYSTEMS USING INFORMATION CRITERIA(2022-12-30) Yakymchuk, Natalia; Selepyna, Yosyp; Yevsiuk, Mykola; Prystupa, Stanislav; Moroz, SerhiiThe successful functioning of telecommunication networks largely depends on the effectiveness of algorithms for detection andprotection against overloads. The article describes the main differences that arise when forecasting, monitoring and managing congestion at the node levelandat the channel level. An algorithm for detecting congestion by estimating the entropy of time distributions of traffic parameters is proposed.The entropy measures of data sets for various types of model distribution, in particular for the Pareto distribution, which optimally describes the behaviorof self-similar random processes, were calculated and analyzed. The advantages of this approach include scalability, sensitivity to changes in distributionsof traffic characteristics and ease of implementation and accessible interpretation.Item type:Наукова стаття, DEVELOPMENT OF A MODIFIED METHOD OF NETWORK TRAFFIC FORMING(2023-03-31) Kozlovskiy, Valeriy; Yakymchuk, Natalia; Selepyna, Yosyp; Moroz, Serhii; Tkachuk, AnatoliiBased on the analysis of the statistical characteristics of heterogeneous network traffic of "Quadruple Play" mobile subscribers, it is shown that it cannot be represented by Poisson or Erlang distributions. It is shown that for such similar traffic, the rate of growth of the required buffer volume increases as the Hurst parameter increases. A method of adaptivetraffic formation using the control of the length of intervals of the intensity of the arrival of data packets has been developed. Congestion management is carried out by changing the frequency of the marker generator (GM) on the basis of the results of forecasting the required bandwidth of the system and the required buffer size. The shaper adapts to changes in the length and instantaneous intensity of packet input in real-time.Item type:Наукова стаття, OVERLOAD AND TRAFFIC MANAGEMENT OF MESSAGE SOURCES WITH DIFFERENT PRIORITY OF SERVICE(2023-09-30) Kozlovskyi, Valerii; Kozlovskyi, Valerii; Toroshanko, Andrii; Toroshanko, Oleksandr; Yakumchuk, NataliaThe scheme of dynamic management of traffic and activity of message sources with different priority of service is considered. The schemeis built on the basis of the neuroprognostic analysis model and the gradient descent method. For prediction and early detection of overload, the apparatus of the general theory of sensitivity with indirect feedback and control of activity of message sourcesis used. The control algorithm is startedat the bottleneck of the network node. It uses a recursive prediction approach where the neural network outputis referred to as many steps as definedby a given prediction horizon. Traffic with a higher priority is served without delay using the entire available bandwidth. Low-priority traffic willuse the remaining bandwidth not used by higher-priority traffic. An algorithm for estimating the maximum available bandwidth of a communication node for traffic with a low service priority has been developed. This approach makes it possible to improve the efficiency of channel use without affectingthe quality of servicefor high-priority traffic.