Наукові статті
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Item type:scientificarticle.listelement.badge, Аналіз факторів, які впливають на чутливість піроелектричних приймачів теплового випромінювання у давачах руху(Луцьк: ЛНТУ, 2024) Мороз, Сергій Анатолійович; Лишук, Віктор Васильович; Чалий, Василь ДмитровичВ статті проведений аналіз одного з різновидів давачів, які використовуються в технологіях Smart City. Зокрема розглянуті давачі на основі піроелектричних приймачів , що реєструють теплове випромінювання, зокрема випромінювання людського тіла. Встановлено, що для оцінки ефективності роботи приймачів випромінювання використовується ряд характеристик, досить важливими з яких є чутливість та поріг чутливості. Наведені математичні відношення, які описують чутливість приймача як комплексну частотну характеристику, що пов’язує реакцію піроелектричного приймача та вплив на нього у вигляді гармонійного потоку. Представлені характеристики порогу чутливості приймача та формули для визначення даної характеристики. Встановлено, що для визначення порогу чутливості піроелектричних приймачів теплового випромінювання необхідно знати рівень шумів його чутливого елемента. Для виведення відповідних формул представлена еквівалентна схема піроелектричного приймача. Встановлені джерела шумів піроелектричних елементів, зокрема тепловий (джонсонівський) шум навантажувального опору, тепловий (джонсонівський) шум опору діелектричних втрат чутливого елементу, шумова ЕРС вимірювальної схеми, ввідний шумовий струм вимірювальної схеми, температурний шум чутливого елементу. Подана графічна залежність величини шумів від різних джерел для типового детектора з електричною та тепловою постійними часу. Зроблені відповідні висновки за результатами аналізу.Item type:scientificarticle.listelement.badge, Аналіз технічних характеристик термодавачів для проектування електронних термометрів(Луцьк: ЛНТУ, 2022) Мороз, Сергій Анатолійович; Заблоцький, Валентин Юрійович; Приступа, Станіслав Олексійович; Євсюк, Микола Миколайович; Лишук, Віктор ВасильовичВ статті проведений аналіз технічних особливостей, які необхідно враховувати під час побудови медичних термометрів. Розглянута класифікація електронних медичних термометрів для вимірювання температури людини. Проведено аналіз термометрів з точки зору їх придатності для моніторингу температурних коливань на поверхні біологічного об'єкту. Розглянута залежність роздільної здатності термометра для різних діапазонів температур. Виявлено, що роздільна здатність термометра (крутизна) пов'язана з його коефіцієнтом передачі. Розширення діапазону вимірюваних температур призводить до зниження коефіцієнта передачі, і навпаки, зниження діапазону призводить до збільшення крутизни в стільки ж разів. Важливо відзначити, що при обмеженій максимальній вихідній напрузі термометра існує сталість відтворення діапазону контрольованих температур ΔT на коефіцієнт перетворення температури в напругу U/°C. Проведений порівняльний аналіз різних типів давачів температури зокрема, перетворювач температура - напруга (TC1047) фірми Micirochip в корпусі SOT23, термодавач (SMT16030) фірми Smartec в корпусі TO18, термістор (203JG1F) фірми NTC в корпусі DO35, (LM19) фірми National Semiconductor в корпусі TO92, і (TSIC306) фірми Hygrosens в корпусі SO8. Розглянуто коефіцієнти інформативності перетворення термодавачів, залежності теплової постійної часу від маси давача в різних видах корпусів. Встановлено, що високу перспективу мають термометри з давачами на основі напівпровідникових діодів, оскільки давачі такого типу забезпечують високу швидкодію, малий час відгуку, роботу в режимі мікрострумів, які максимально зменшують саморозігрів давача, високу чутливість, хорошу лінійність в заданому діапазоні температур (25-40 °С), стабільність електричних параметрів. Поряд з високими експлуатаційними характеристиками давачів на основі напівпровідникового діода мають невисоку вартість.Item type:scientificarticle.listelement.badge, The Mathematical Model Development of Modular Three-Link Trailer Truck Train Motion(2026) Gandziuk, Mykola; Onyshchuk, Vasyl; Zabolotnyi, Oleg; Tkachuk, Anatolii; Grabovets, VitaliyIn the case when a multi-link vehicle consists of 3 links or more, the study of their movement is significantly complicated, since the number of factors that influence the nature of the movement of the constituent links of the road train significantly increases. During the movement of a multi-link vehicle the force interaction between its adjacent links significantly affects the entire road train, which can lead to significant deviations of its links from the movement direction set by the tractor truck. Road trains are a type of transport with increased danger, therefore, when designing and researching multi-link vehicles, it is necessary to conduct detailed theoretical and numerous experimental studies of the dynamics of their movement, which will become the basis for predicting their behavior in real conditions. Proceeding from the above, the layout scheme of a road train with 3-axle tractor, 2-axle trolley and 3-axle semi-trailer as universal and promising (developed by the companies “Scania” and “Krone”) was chosen to study its movement and develop a mathematical model of movement. This model will allow us to theoretically predict and determine the influence of our layout scheme and driving modes of 3-link road train on its operational properties. At first time the subject of mathematical modeling became the three-link road truck train with a two-axle trolley and a coupling point located outside the tractor base. This configuration was not the object of in-depth analysis in previous works. This study is comprehensive in nature and demonstrates a number of aspects that distinguish the proposed approach against the background of existing scientific developments in the field of transport system dynamics.Item type:scientificarticle.listelement.badge, A Method of Body Parts Force Displacements Calculation of Metal-Cutting Machine Tools Using CAD and CAE Technologies(2019-10-01) Chetverzhuk, Taras; Zabolotnyi, Oleg; Sychuk, Viktor; Polinkevych, Roman; Tkachuk, AnatoliiThis paper describes a developed new method of body parts force displacements calculation of metal-cutting machine tools using combination of CAD and CAE technologies. It was carried out the analysis of analytical methods and the method of finite elements of body parts force displacements calculation of metal-cutting machine tools. On the basis of it the requirements to the method of calculation of compound errors of processing and deviations of the form of the processed surfaces due to deformations of the body parts of metal-cutting machines are established. The method of designing metal-cutting machines is grounded, which is based on mathematical modeling of different processes. It gives an opportunity to evaluate the accuracy of the machine and the impact on it of the individual assembly already in the initial stages of designing. The calculation methodology was implemented using ANSYS finite element analysis. This technique was used in the calculations on the example of high-precision lathesItem type:scientificarticle.listelement.badge, Distribution of the Surface Current Density in the Plate of a Quartz Resonator(2024-10-11) Prystupa, Stanislav; Tkachuk, Anatolii; Selepyna, Yosyp; Moroz, Sergiy; Vynnychenko, Ihor; Zabolotnyi, OlegThe basis of most thermostated quartz oscillators is quartz resonators of two-turn cuts TD, SC, and AT. Resonators based on crystalline elements of these cuts, compared to resonators based on the most popular AT cut, have the main advantage – less influence of climatic and mechanical influences on the frequency, which explains their widespread use. At the same time, double-turn cut resonators have one significant drawback - insufficient mono-frequency, associated with a higher quality factor and low dynamic resistance of the side oscillation (mode B) compared to the main oscillation (mode C). Since the frequency of the secondary oscillation is only ~10% higher than the frequency of the main one, the oscillator circuit has to be complicated by introducing additional selective elements into it, mainly resonant circuits based on inductors. The purpose of the work is a theoretical study of the physical properties of the quartz element of the resonator, namely the calculation of the surface current density on the surface of the crystal element in different modes of oscillation. It has been established that the distributions of current densities over the surface of the piezoelectric element of the side mode B and the working mode C differ from each other and are asymmetrical relative to the center of the piezoelectric elementItem type:scientificarticle.listelement.badge, Formation of Bearings Parts Waviness in Centerless Mortise Grinding on Rigid Supports(2023) Chalyj, Vasyl; Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Trokhymchuk, Ivanna; Stelmakh, OleksandrThe formation of corrugation of the working surfaces of bearing parts is associated with fluctuations in the size of the cut layer of metal and changes in the components of the cutting force. Laplace operators were used to model the centerless grinding system, on the basis of which the transfer function and the characteristic equation were constructed. It was found that the formation of waviness depends on the position of the hodograph of the movement of the vector of the center of the part in the complex plane, which in turn depends on the geometric parameters of the rigid supports of the centerless grinder machine. This makes it possible on the basis of hodographs and the angular orientation of their asymptotes to determine the geometric stability of the process depending on the angles of adjustment of the rigid supports of the grinder machine. To confirm the correctness of the hypotheses, two methodological approaches were used: multiplication of hodographs of wave and regeneration displacement and coincidence of the combined hodograph of regeneration and waviness displacement mechanisms with the hodograph of infinitely rigid machine displacement. The diagrams which allow choosing geometry of adjust-ment of rigid support that allows to increase or decrease parameters of certain harmonics are developed. The three-dimensional diagram allows you to set the local minima, which are characterized by acceptable geometric conditions of adjustment, providing regulated waviness of the working surfaces of bearing parts.Item type:scientificarticle.listelement.badge, Influence of Turning Operations on Waviness Characteristics of Working Surfaces of Rolling Bearings(2022) Zablotskyi, Valentyn; Tkachuk, Anatolii; Prozorovskyi, Serhii; Tkachuk, Valentyna; Waszkowiak, MarekThe formation of micro and macro geometric parameters of conjugate cylindrical surfaces of parts is technological movements of equipment that provide the specified quality characteristics of parts. The waviness of the part’s surface is one of the critical geometric characteristics, which provides the functional features of the unit as a whole, as it affects the vibration processes that occur during operation. The ripple is formed under the influence of dynamic processes of processing of details which are characteristic of metalworking machines, depending on changes in system machine-tool (cutting)-part (MTP). Mechanical perturbations during cutting occur due to forced oscillations, self-oscillations, deformation of the rings due to the action of cutting forces. Self-oscillations occur due to the loss of properties of a given motion during cutting and forced oscillations due to external factors. The undulation of the surface is formed due to forced oscillations of the metal-cutting system due to periodic perturbations that occur due to disbalances of the MTP system’s parts. The ratio of the oscillation frequency for relative motions of the tool and the part can change the law of oscillating motion and the shape of the surface. The decisive factor influencing the formation of geometric errors of the part is the ratio of the frequency of harmonic oscillations of the tool and the workpiece to the frequency of rotation of the machine tool’s spindle.Item type:scientificarticle.listelement.badge, ЕLECTROMAGNETIC FIELD EQUATIONS IN NONLINEAR ENVIRONMENT(Politechnika Lubelska, 2024-03-31) Lyshuk, Viktor; Tchaban, Vasyl; Tkachuk, Anatolii; Zablotskyi, Valentyn; Selepyna, YosypThe paper proposes electromagnetic field equations from the point of view of their adaptation to numerical methods. Maxwell’s equations with partial derivatives are used, written concerning field vectors, which most fully reproduce the picture of physical processes in electrical engineering devices. 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 rules of 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 machine.Item type:scientificarticle.listelement.badge, Investigation of Features of Functioning of the Pyroelectric Sensors in Electronic Security Devices(2021-05-19) Moroz, Serhii; Khvyshchun, Mykola; Tkachuk, Anatolii; Lyshuk, Viktor; Prystupa, StanislavThe article reviews and studies the operation of pyroelectric sensors in electronic security devices. The main focus is on pyrodetectors that detect infrared radiation from the human body. To eliminate background thermal radiation, the pyroreceiver must consist of two crystals. In addition, pyroreceivers must have internal correction circuits that attenuate the high-frequency components of the signals. Establishing the main parameters of thermal radiation, which is perceived by the pyroreceiver.Item type:scientificarticle.listelement.badge, Methods for Ensuring Data Security in Mobile Standards(2022-03-31) Moroz, Serhii; Tkachuk, Anatolii; Khvyshchun, Mykola; Prystupa, Stanislav; Yevsiuk, MykolaThe analysis of mobile communication standards is carried out, the functional structure and interfaces of interaction between the structural elements of the cellular network are considered. To understand the principle of communication according to the GSM standard, a block diagram of a mobile switching center (MSC), base station equipment (BSS), control and service center (MCC), mobile stations (MS) is presented. The main algorithms for ensuring the confidentiality and security of mobile subscribers' data, in different types of standards, as well as the vulnerabilities of information flows are considered. In particular, the following dangerous types of attacks have been identified, to which mobile network subscribers are sensitive: sniffing; leakage of personal data; leakage of geolocation data; spoofing; remote capture of SIM-card, execution of arbitrary code (RCE); denial of service (DoS). It is established that the necessary function of the mobile network is the identification of subscribers, which is performed by IMSI, which is recorded in the SIM card of the subscriber and the HLR of the operator. To protect against spoofing, the network authenticates the subscriber before starting its service. In the case of subscriber identification, the subscriber and the network operator are protected from the effects of fraudulent access. In addition, the user must be protected from eavesdropping. This is achieved by encrypting the data transmitted over the radio interface. Thus, user authentication in UMTS, as well as in the GSM network, is carried out using encryption with a common key using the "hack-response" protocol (the authenticating party sends a random number to the authenticated party, which encrypts it according to a certain algorithm using a common key and returns the result back).