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Item type:Наукова стаття, Mathematical Modeling and Experimental Analysis of the Thread Take-up Function in Single-thread Chain Stitch Sewing Machines Type 101(2026-03) Manoilenko, Oleksandr; Horobets, Vasyl; Puts, Vitalii; Volokh, Lyudmyla; Bezuhlyi, Dmytro; Bilashov, Konstantyn; Pleshko, SerhiyAn analytical and experimental methodology for evaluating functional characteristics of the single-thread chain stitch formation process (type 101) is proposed. The evaluation is based on degree of correspondence between the required and actual thread take-up, which reflects the machine’s efficiency and the quality of stitch formation. A measuring system and an experimental procedure were developed to record thread take-up under different material thicknesses and stitch lengths. The obtained dependencies were approximated by sixth-degree polynomials with high accuracy (R² > 0.99), which made it possible to construct mathematical models of the thread take-up process. For GK-9 type machines, excessive thread take-up (20–64% above the required value) was set up, causing uneven thread tension and reduced stitch stability. The proposed methodology ensures quantitative evaluation, prediction, and regulation of thread take-up process, which improves functional efficiency of sewing machines and supports development of adaptive thread take-up control systems.Item type:Наукова стаття, On the dynamics of vibrational capture of rotation of an unbalanced rotor(2022-05-16) Yaroshevich, Nikolay; Gursky, Volodymyr; Puts, Vitalii; Yaroshevych, Olha; Martyniuk, ViktorStationary (near stationary) rotation modes of an unbalanced rotor with the oscillation frequency of its axis are considered. From the standpoint of I. I. Blekhman vibrational mechanics, explanations of the mechanism of vibrational capture of the rotation of an unbalanced rotor are given. It is demonstrated that the vibration moment arising as a result of oscillations tends to synchronize vibrational and rotational movements. In addition its effect in the stationary mode becomes unambiguous – either braking or accelerating. It is shown that when a stationary rotation mode is established, large, relatively slow oscillations of rotor’s speed can occur. Theoretical results are confirmed by computer simulation.Item type:Наукова стаття, Optimization of pickup parameters for flax retted straw formation(2026) Didukh, Volodymyr; Bodak, Maksym; Khlopetskyi, Roman; Tsiz, Igor; Tarasiuk, VictorClimatic characteristics, particularly temperature and ambient humidity, significantly affect the qualitative and quantitative indicators of flax production and fibre formation. Conventional technologies for obtaining flax fibre are based on natural dew retting, the efficiency of which depends on atmospheric moisture. The decrease in air humidity during summer periods due to climate change complicates the biological processes involved in the transformation of flax stems into retted straw. A separate harvesting technology involving low cutting of stems and their placement into windrows has been proposed to utilize productive soil moisture during retting and to accelerate seed harvesting. During field laying, windrows change their geometric parameters, become denser, and increase adhesion both between stems and with the soil surface, which requires periodic lifting and loosening. This paper presents the results of field experimental studies conducted using a developed experimental picker to determine rational structural and technological parameters based on a four-factor experimental design. Changes in windrow geometry and their interaction with the working elements of the picker were analysed. Optimal parameters of the picker for flax retting preparation were established. The study is aimed at developing a new technical solution for flax harvesting.Item type:Наукова стаття, Construction of the Geometrical Models of a Multiple-Factor Optimization of the Technical and Operating Parameters of the Trolleybuses with an Autonomous Move Margin(2022) Serhii, Pustiulha; Volodymyr, Samchuk; Valerii, Dembitsky; Viktor, Samostian; Valentyn, PrydiukWhile introducing into a system of passenger traffic the ecologically clean vehicles, namely the electric buses, a task of providing them with a rational move margin is actual. This problem is especially acute while using the trolleybuses with an autonomous move at urban and suburban routes. A constructed multiple-factor model and a proposed algorithm of finding the main parameters allow forming the offers concerning a constructive providing of an additional equipment process with the means of autonomous move. Based on a visual presentation of the multidimensional spaces at Radishchev drawing an effective way is offered of a geometrical interpretation of mutual influence of the optimization factors set on the operating characteristics of the additionally equipped vehicles.Item type:Наукова стаття, Maneuverability and Movement Stability of Buses of the Especially Large Size Class(2024) Volodymyr, Sakhno; Igor, Murovanyi; Galina, Filipova; Victor, Poliakov; Valerii, DembitskiyOne of the main problems of modern big city is the global crisis of normal urban environment operation as a result of structural growing of automobilization level, oversaturation of road-street network by the transport streams. Buses of the especially large size class occupy, at the least, 20% in the structure of a modern bus park. The buses of especially large size classes, with the aim of necessary maneuverability, as a rule are made articulated. One of the ways of improving the maneuverability of articulated buses is the usage of guided towed sections. Solving the mentioned problem usually needs the mathematic models for predicting the vehicle behavior. The aim of introducing the trailer direction is to increase the overall traffic lane of an articulated bus that ensures a necessary maneuverability. The aim is gained by a choice of a rational transmitting ratio of trailer axle gear and necessary value of braking moment on one of its wheels. The solving of the problem concerning the stability of an articulated bus with a guided trailer axle was made by the way of analyzing the linear approaching of stationary vehicle movement. An influence of the construction parameters of the bus and the trailer, a transmitting ratio of control gear and a value of braking moment on the parameters of bus maneuverability were analyzed. It was proved that for an articulated bus, the normal maneuverability parameters can be ensured at the trailer direction by a way of braking of one of the wheels.Item type:Наукова стаття, Comparative Estimation of Maneuverability of the Multi-Track Road Trains of Different Layout Schemes(2025) Sakhno, Volodymyr; Murovanyi, Igor; Razboinikov, Oleksandr; Palamarchyk, Olekcii; Dembitskyi, ValeriiToday, in the constructions of multi-link road trains, two main layout schemes are used, as a rule - trailer (car + n trailers) and semi-trailer (tractor car + n semi-trailers). Previously conducted studies established that the maneuverability indicators of the road trains can be determined on wheels rigid in the lateral direction, that is, according to kinematic models, which are based on the angles of assembly of the road train links. These angles are defined for both a three-link trailer and a semi-trailer vehicle train, for different locations of the extended link. For the semi-trailer road trains, the requirements for maneuverability are not met, and therefore the trailer links must be equipped with more or less complex control systems. With a direct control drive on the front axles of the second and third semi-trailers, when turning at 90º and 180º, only the first layout scheme satisfies the requirements for maneuverability.