Browsing by Author "Lukoševičius, Vaidas"

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Assessing Tractors’ Active Safety in Serbia: A Driving Simulator Study
(MDPI, Basel, Switzerland, 2025) Simović, Sreten; Trifunović, Aleksandar; Ivanišević, Tijana; Lukoševičius, Vaidas; Neduzha, Larysa
ENG: The active safety of tractors remains a major concern in rural road environments, where tractor drivers face high crash risks due to limited vehicle visibility. In Serbia, 1.4% of crashes involve tractors, mainly due to poor visibility (64.3%), lack of beacon lights, unsafe overtaking, and unmarked stopped tractors (14.3% each). These issues reduce safety, increase fuel consumption and emissions, and cause economic losses. A driving simulator study with 117 drivers examined how visibility equipment affects speed perception. The results showed that 20 km/h was best estimated with all visibility aids, while 10 km/h was most accurately judged with only the slow-moving vehicle emblem. These findings emphasize the potential for simple, cost-effective visibility measures to enhance the active safety of tractors in mixed rural traffic conditions. By enhancing tractor visibility, these measures reduce crash risks, minimize unnecessary acceleration and deceleration, and lower fuel consumption and emissions associated with traffic disturbances. Furthermore, by preventing crashes, these solutions contribute to reducing resource consumption in crash-related medical care, vehicle repairs, and infrastructure damage. Integrating improved visibility equipment into rural traffic policy can significantly enhance tractors’ active safety and reduce the risk of crashes in agricultural regions.
Conceptual Basis of Adaptation of a Field-Oriented Control System for Traction Induction Motors to the Operating Parameters of a Locomotive
(MDPI, 2026) Lukoševičius, Vaidas; Goolak, Sergey O.; Derehuz, Ihor; Neduzha, Larysa O.; Keršys, Artūras; Dzerkelis, Vytautas
ENG: Field-oriented control (FOC) of induction motors (IMs) is used in railway rolling stock. In such control systems, a fixed frequency of the pulse-width modulation (PWM) inverter is used, which leads to an increase in power losses in the traction drive. To optimize power losses in the locomotive traction drive system, it is proposed to adapt the number of PWM inverter pulses to the frequency of the FOC speed controller, which is proportional to the locomotive speed. To solve this problem, conceptual foundations for adapting FOC to the locomotive speed have been developed, the key aspects of which are algorithms for adapting the PWM inverter frequency, the controller parameters and the parameters of the FOC speed controller frequency filters. The most significant results of the work are the methods for adjusting the maximum of the controllers of the basic FOC IM system, the filter structure and the inverter control scheme, adapted to the locomotive speed. The modeling results have shown the effectiveness of the proposed technical solutions. The proposed approach to developing FOC will allow minimizing the consumption of energy resources by the locomotive in the entire range of changes in its speed.
Innovative Trends in Railway Condition Monitoring
(ELSEVIER B. V., 2024) Bondarenko, Iryna; Lukoševičius, Vaidas; Keršys, Robertas; Neduzha, Larysa
ENG: Provision of functional safety of a railway track requires complementing the existing system of assessment of the railway track condition with the stress-strain behaviour assessment of the rail substructure, i.e. the assessment of the effect of track structure elasticity on the change of its geometric parameters during rolling stock passage over time. There is a lack of available theoretical and practical information about any pivotal changes in this field of science. The subject of the study is the in-situ elasticity indicators of a railway track and geometric monitoring indicators of railway structure condition or similar indicators obtained by numerical processing of data provided by the measuring systems of a track recording car and enabling the determination of change of irregularity parameters over time taking into account of the tonnage passed. The outcome of the investigation is the proposed approach to the development of an unparalleled diagnostic loading system which has been the missing part of the “puzzle” in the existing system of integrated assessment of the technical condition of a railway track.
Investigation of Dynamic Processes of Rolling Stock–Track Interaction: Experimental Realization
(MDPI, 2023) Bondarenko, Iryna; Lukoševičius, Vaidas; Keršys, Robertas; Neduzha, Larysa
ENG: The dynamic process of the railway track–rolling stock interaction is characterized by timedependent dynamics that are determined by both the varying characteristics of the interaction objects and the varying climatic conditions. This study investigated the effect of different groups of influence on the dynamic process, with a view towards the reduction of the cases of randomness during the registration of the process in experiments and an expansion of the understanding of the processes happening during the assessment of the registered data. The static nature of the rolling stock has been demonstrated to be not uniform and to influence the scattering of dynamic values under the variation of vertical and horizontal forces due to the characteristics of a rolling stock. The position of the rolling stock truck relative to the track axis during the movement of the rolling stock has been shown to enhance static non-uniformity. The results of the longitudinal force measurements under the three-point and Schlumpf methods have suggested that it is necessary to investigate the process of rail warping under the action of the rolling stock wheels. To enhance the output of the experiments, it is proposed to consider not only the stiffness of the basis of the oscillatory processes that imitate the physical process of oscillation of the system elements by means of the oscillation amplitude, but also the time of response to the oscillation process by using and assessing the triggering time rather than the frequencies of the oscillation processes.
Novel ‘Closed’-System Approach for Monitoring the Technical Condition of Railway Tracks
(MDPI, Basel, Switzerland, 2024) Bondarenko, Iryna; Lukoševičius, Vaidas; Neduzha, Larysa
ENG: Assessing the technical condition of a railway track throughout its service life is crucial to ensuring functional safety. However, it is important to note that current approaches have theoretical and practical gaps that require attention. The purpose of this study is to discuss the reconceptualization of an integrated approach to assess changes in the technical condition of railway tracks caused by rolling stock over their service life. Improving existing systems for assessing the condition of the track can be achieved by modifying the model concept and, subsequently, the measurement and assessment procedures. This paper presents an alternative method for addressing technical issues related to the monitoring and diagnosis of railway tracks, with a particular focus on natural phenomena: energy transfer by elastic waves. The primary aim of this work is to propose an approach for designing a ‘closed’ measurement system that enables tracking of the cause-and-effect relationship. This system takes into account both the elastic dissipative characteristics of the track–rolling stock interaction and the influence of the dynamics of various components in the ‘train-track’ system.
Rationale for New Pontoon-Cable Bridge Structure Parameters for Providing Uninterrupted Transportation
(University of Padua, 2025) Ovchynnykov, Pavlo A.; Tiutkin, Oleksii L.; Lukoševičius, Vaidas; Neduzha, Larysa O.
ENG: A novel type of pontoon bridge was proposed, characterized by fully submerged pontoons, creating excessive buoyant forces, and overdeck cable intended for keeping them from surfacing. Various scheme configurations were calculated using FEM to determine structure's behaviour and substantiate its parameters. Result show increased rigidity, when compared to traditional floating bridges, which translates into improved passenger comfort and overall usability.