Bulletin of Lviv National Environmental University. Series Agroengineering Research

REMOTE ADJUSTMENT OF OPERATING MODES OF THE INERTIAL DRIVE IN VIBRATORY MACHINES FOR PART PROCESSING

P. Koruniak, R. Sheremeta , S. Berezovetskyi , O. Shvets — Mon, 01 Dec 2025 00:00:00 +0200

The paper addresses the urgent task of improving the design of a single-shaft unbalanced vibration drive for vibration machines used in modern mechanical engineering to intensify processes of mechanical treatment of parts. The proposed structural solution provides the possibility of remote and automated adjustment of the oscillation amplitude of the working body by changing the relative angle between the unbalances mounted on the drive shaft. The use of an industrial microcontroller enables the tuning of vibration treatment modes both before the start of a technological operation and directly during the working cycle, which significantly increases the flexibility and efficiency of the process.

The current research shows that the effectiveness of vibration treatment is determined by a complex of parameters - amplitude, frequency, and oscillation form, as well as the characteristics of the parts and the working medium. Traditional unbalanced drives have limited adjustment capabilities, which reduces surface quality and shortens equipment service life. The proposed design eliminates these drawbacks through the use of an electromagnetic actuator and a stepper engine, which ensure precise positioning of the movable unbalances and stabilization of the oscillation amplitude. This allows maintaining optimal technological regimes, avoiding overloads, and ensuring high surface quality even for parts with complex configurations.

The implementation of the developed solution into the design of the vibration exciter opens up opportunities for creating a new generation of vibration machines with automated control of process parameters. Such an approach contributes to increased energy efficiency, expanded technological capabilities of equipment, and provides prospects for its use in multipurpose production complexes. The findings of the study can be applied both to update existing machines and to develop new samples of vibration technology with improved technical and economic indicators.

STATIC INTERACTION BETWEEN THE TINES OF A FORK AND A GARLIC CLOVE

Ya. Semen , О. Krupych, O. Semen — Mon, 01 Dec 2025 00:00:00 +0200

The proposed scientific study significantly contributes to the ongoing research aimed at developing mechanized techniques for the individual planting of garlic cloves. This work is built upon analytical research focused on determining the volume, mass, and coordinates of the center of gravity of garlic cloves, which are formed on the central core of the garlic head. This is considered within a Cartesian coordinate system as part of a sphere of the corresponding radius. The study examines the interactions within the "drum - garlic clove - fork" system and explores how the roller of the fork rod interacts with the various profile surfaces of the planting device guides in the proposed planter design.

The article presents findings on the interaction between the forks of the planting device, which is designed for forced, individually oriented planting of garlic cloves with the bottom facing down and the sprout facing up. These forks are lined on the inside with an elastic material that interacts with the garlic clove. An analytical method is employed to address the contact problem arising from the interaction of two anisotropic bodies of differing densities, each characterized by its respective Young's modulus and Poisson's ratio.

A calculation scheme is provided, illustrating the contact area between a garlic clove and the elastic material of the fork tines in the shape of an ellipse. The parameters of this ellipse's semi-axes depend on the size and shape of various garlic varieties. The study also accounts for the fact that the principal radii of curvature of the garlic clove's surface and the elastic element of the fork tines are known, and that the main contact planes of the surfaces involved coincide.

The conducted theoretical analyses have resulted in analytical relationships that enable the determination of the maximum pinching force exerted on a garlic clove between the tines of the fork. This is contingent on ensuring that the resulting stresses remain below permissible limits. Additionally, the research identifies the necessary stiffness of the spring required to securely hold the garlic clove between the fork tines during in-machine transportation and direct insertion into pre-formed grooves.

STATIC INTERACTION BETWEEN THE TINES OF A FORK AND A GARLIC CLOVE

А. Tryhuba , A. Sharybura , Z. Hoshko , О. Levchuk , R. Barabash — Mon, 01 Dec 2025 00:00:00 +0200

ANALYSIS OF THE DYNAMICS OF THE MAJOR TYPES OF WORKPLACE ACCIDENTS, ACUTE OCCUPATIONAL DISEASES (SUCH AS POISONINGS), AND OTHER INCIDENTS

І. Horodetskyi, V. Tymochko , І. Okipnyi , О. Shvets , О. Burnaiev, V. Semerak — Mon, 01 Dec 2025 00:00:00 +0200

The study reviews the current state of research on industrial injuries, particularly within sectors like energy, agriculture, and road transport. The analysis emphasizes the need to better characterize the causes of accidents and dangerous events. Various methods for classifying harmful and dangerous production factors are highlighted, alongside inconsistencies found in regulatory legal acts. A classification of dangerous events, which includes 24 categories, is also provided. The analysis reveals that the most prevalent and dangerous events between 2017 and 2021 were as follows: 1. employee falls (747-1095 incidents); 2. falling objects and materials on victims (418-593 incidents); 3. vehicle-related accidents (293-482 incidents); 4. falls from height (319-413 incidents); 5. incidents involving moving objects and parts. Other events with a significant number of fatal consequences included electric shocks (27 deaths in 2018 and 24 in 2022), as well as fatalities from fires (4 and 12 people respectively), health deterioration (14 and 13), explosions (3 and 11), and exposure to harmful and toxic substances (8 and 6). The financial impact of accidents on enterprises was also examined, showing costs ranging from 566,600.27 thousand UAH in 2019 to 212,376.35 thousand UAH in 2021. There was an increase in compensation claims, as indicated by certificates of incapacity, rising from 94,293.02 thousand UAH to 190,059.51 thousand UAH during the analyzed years. Significant expenses were incurred for equipment, tools, and the destruction of buildings and structures due to accidents, while fines imposed on officials for violating labor safety legislation were relatively minor. In 2022, the highest number of fatalities occurred during public life events, such as war, terrorist acts, and blockades, resulting in 156 deaths. Key regulatory legal acts (including rules, regulations, norms, orders, standards, and instructions) have been identified, compliance with which can help mitigate the impact of dangerous and harmful production factors on employees. Future research should focus on analyzing the patterns and circumstances surrounding the occurrence of dangerous events to develop measures to decrease their frequency.

INTELLECTUAL MODELS FOR THE DEVELOPMENT OF SECURITY SYSTEMS AND ENERGY AUTONOMY IN RURAL COMMUNITIES

Mon, 01 Dec 2025 00:00:00 +0200

An analysis of existing approaches to spatial planning of security systems and energy autonomy of rural communities has been carried out. It has been established that traditional methods of deploying rescue teams and planning energy consumption are mostly based on average indicators and do not take into account various scenarios or the complex impact of multiple risk factors. The feasibility of using intelligent models, in particular p-center, p-median, recurrent neural networks (LSTM), and hybrid algorithms, has been substantiated. These models allow minimizing response time to emergencies, balancing the energy load of facilities, and predicting the level of community autonomy. The Python program developed provides spatial modeling of the availability of volunteer rescue teams using OpenStreetMap geospatial data and optimization methods. According to the results of modeling in Sheptytskyi urban community of Lviv region, it was established that the maximum response time to emergencies was reduced from 27 to 15 minutes, the average response time from 18 to 12 minutes, the proportion of the population covered within a 15-minute drive of rescuers increased from 54% to 82%, and the protection of critical infrastructure facilities increased from 61% to 89%. This confirms the effectiveness of the p-center model for territories with scattered settlements and demonstrates the practical significance of the proposed approach for community security and development strategies. Further research should focus on integrating energy balance forecasting models with algorithms for selecting locations for renewable energy sources, which will create a unified toolkit in the form of a decision support system for community project managers.

USING ARTIFICIAL INTELLIGENCE IN EDUCATIONAL PROJECTS AND THE DIGITAL TRANSFORMATION OF UNIVERSITIES: EXPERIENCE OF INTEGRATING AN AI CHATBOT BASED ON OPENAI

Mon, 01 Dec 2025 00:00:00 +0200

As part of the digital transformation and automation of information support for applicants, an interactive chatbot based on OpenAI's GPT-4 model was developed and implemented on the official WordPress website of the University. The primary goal of this initiative is to enhance communication efficiency between the University and prospective students, while also providing prompt responses to common questions without requiring additional human resources. In this study, the GPT AI Power plugin was utilized to send requests to the OpenAI API using a specially designed prompt. The results are displayed through a user-friendly dialog interface.

A comprehensive database of questions and answers was created, addressing key aspects of the admission campaign, such as minimum passing scores, the necessity of submitting a motivation letter, and the rules for creating and submitting electronic applications via the unified system vstup.edbo.gov.ua. This dataset serves as context for generating relevant responses, allowing the model to be tailored to the specific educational processes of the University. Furthermore, a system of hidden fields and dynamic parameters was implemented to customize personalized messages for different pages of the website related to various specialties.

From a technical standpoint, integration with the OpenAI API was successfully established, processing each request in real time and returning responses based on predefined instructions. This integration ensures system stability and the high relevance of responses. Additionally, testing was conducted to evaluate response speed, server load, and visitor engagement on the website before and after the chatbot's implementation. Results indicate an increase in user interaction and improved applicant satisfaction, as confirmed by statistical data outlining the number of queries and time spent on the website.

This solution serves as a practical example of leveraging artificial intelligence technology in the field of education, aligning with current trends in the digital transformation of universities. It illustrates the technical benefits of integrating an AI system into the University's web infrastructure, such as real-time automated processing of applicant inquiries, operational stability through OpenAI API usage, and flexibility in knowledge base formation. These features contribute to high response speed and accurate information delivery. In the socio-economic context, this development enhances convenience, accessibility, and scalability, significantly improving the quality of support for applicants while reducing the workload on admissions staff, thus facilitating the effective digital transformation of the University.

EFFECTIVENESS OF OBJECT-ORIENTED PROGRAMMING METHODS AND PATTERNS FOR PLANNING RURAL RESCUE TEAMS

А. Tryhuba , L. Koval, А. Tatomyr, О. Boiarchuk , R. Padiuka, V. Stanko — Mon, 01 Dec 2025 00:00:00 +0200

The article substantiates an approach to improving the effectiveness of software models designed for planning voluntary rescue teams in rural communities based on the integration of object-oriented programming methods and design patterns. It is shown that combining SOLID principles with the use of Strategy and Observer patterns significantly reduces architectural complexity and creates the conditions for developing scalable and flexible solutions that can adapt to changes in algorithms and external conditions. The software modules implemented in Python 3.12 allowed for an experimental assessment of the impact of programming approaches on key system quality indicators. The research was carried out using the example of tasks for planning the location of volunteer rescue teams for Sheptytskyi urban territorial community in Lviv region. The results prove that the use of classical procedural approaches is not effective enough, since such systems are characterized by low flexibility, significant maintenance costs, and poor code reuse capabilities. The transition to classic object-oriented programming (OOP) significantly improves performance, but the maximum effect is achieved by integrating OOP with patterns, which has increased the quality of implementation to 0.92, scalability to 0.89, component reuse to 0.91, and at the same time reduced the complexity of the architecture to 0.40. This confirms the feasibility of implementing patterns for building modern information systems in the field of security and planning rescue infrastructure in rural communities. The practical significance lies in the possibility of further integration of the developed modules into systems for spatial modeling and optimization of rescue formations. Research prospects include expanding the set of optimization algorithms, applying stochastic and robust methods, and using dynamic spatial data to form a comprehensive set of tools to support management decisions for communities.

APPROACHES TO DESIGNING A WEB-BASED CUSTOMER SUPPORT SYSTEM FOR THE AGRICULTURAL SECTOR

А. Zhelyeznyak , R. Padiuka , Kh. Dzioba — Mon, 01 Dec 2025 00:00:00 +0200

This paper examines and analyzes approaches to the design, development, and operation of web-based customer support systems for agricultural enterprises. It examines prevailing practices and methodologies in the design and implementation of website-based user support solutions, identifying technologies that promote the advancement of customer support services in the agricultural sector. It has been established that the primary forms of support systems for producers and the population engaged in agriculture are digital platforms, cooperative systems, and advisory services. Furthermore, the study outlines the most common models of customer support systems, including the self-service model, interactive support model, and hybrid model, and evaluates their respective advantages and limitations. Finally, it highlights the key challenges encountered by developers in creating web-oriented customer support systems.

Arguments are presented for the feasibility of using generative artificial intelligence technologies to improve the personalized approach to customer support. The roles and tasks of “live” agents and digital assistants as the most common forms of support for users of commercial Internet resources, are clarified. The features of using digital assistants are considered in comparison to such traditional forms of customer support as telephone lines, messengers, and consultants. The importance of segmenting agricultural enterprise customers as an important element of the support system planning and design process is substantiated. The key components of the customer support system are analyzed, and the main functions and options for their implementation are considered.

The findings highlight the necessity of a comprehensive approach to designing Internet-based customer support systems for agricultural producers, taking into account the specific nature of their activities, the potential of modern technologies, the frequency and volume of user requests, and the available resources.

RESTFUL API PERFORMANCE MODELING: REQUEST PROCESSING ALGORITHMS AND DATA ANALYSIS

P. Lub , V. Fialkovskyi , L. Chukhrai , S. Shtohryn , V. Stefanyshyn — Mon, 01 Dec 2025 00:00:00 +0200

The text summarizes the positive and negative aspects of creating RESTful APIs in back-end development. It analyzes the current state of REST architecture usage in web technologies and examines modern approaches and tools for developing RESTful APIs, justifying their applicability. Popular frameworks and development environments, such as Express.js, Django REST Framework, and Spring Boot, which are widely used in both startups and large companies, are described. The study highlights key features such as request structuring, HTTP methods, routing standards, and server-side data handling. It emphasizes RESTful APIs for their ease of integration, scalability, and flexibility in client-server application development. The key principles of RESTful API design are outlined, including the use of the GET, POST, PUT, and DELETE methods, proper server response formatting, and standardization of resource paths. Some limitations of the REST approach are noted, such as challenges in handling a large number of resources and issues related to API versioning. The use of these tools and approaches improves the quality of server-side logic, ensures standardized data exchange, and reduces complexity in client-side integration. The application of RESTful APIs in modern web design through frameworks like Express.js, Django REST Framework, and Spring Boot is characterized. A practical example is provided of a small Node.js server using Express to manage a task list with basic CRUD operations. The focus is on optimizing REST requests through various strategies, including caching, pagination, filtering, batch requests, data compression, and asynchronous processing. A methodology for evaluating API performance on a Node.js/Express test server, using Prometheus and Grafana for monitoring, is described. Load testing with a stable request stream allowed for the assessment of the impact of individual optimization methods on throughput, latency, and data volume. Results indicate that asynchronous requests and batch operations yield the highest performance increases, while caching, pagination, filtering, and compression offer moderate improvements. It is emphasized that utilizing combined optimization methods significantly enhances speed, reduces response time and server load, and ensures stable operation of web services, even under conditions of high traffic intensity.

ALGORITHMIC METHODS OF PARALLEL PROCESSING OF BIG DATA IN PREDICTIVE ANALYTICS SYSTEMS

Mon, 01 Dec 2025 00:00:00 +0200

The rapid growth of data volumes and the increasing complexity of predictive and analytical models necessitate the efficient use of parallel processing in modern information systems. The aim of this paper is to substantiate algorithmic and architectural approaches to parallel processing of big data in predictive analytics systems, taking into account performance, scalability, and adaptability requirements. The study provides an analytical comparison of parallelism models, software frameworks, and computing architectures, and examines system-level constraints that affect the efficiency of predictive analytics systems in distributed and heterogeneous environments. It is shown that isolated scaling of computational resources does not ensure proportional performance gains, whereas the highest efficiency is achieved by hybrid configurations that combine multiple parallelism models with hardware accelerators. The scientific novelty of the study lies in the systematization of algorithmic and architectural approaches to parallel big data processing in predictive analytics with consideration of adaptability and system constraints, as well as in the formulation of an integrated analytical approach to combining software platforms and specialized computing architectures. The obtained results can be applied to the design of high-performance predictive analytics systems. The article also outlines directions for the further development of parallel predictive and analytical systems, in particular in the context of integrating machine learning methods, stream data processing, and dynamic management of computational resources. Special attention is paid to aligning algorithmic solutions with the characteristics of the hardware platform to minimize overhead costs and improve the energy efficiency of computations. The proposed analytical approach can serve as a methodological basis for building adaptive high-performance predictive analytics systems under conditions of variable workloads and heterogeneous computational environments.

CONCEPTUAL MODEL OF RISK-ORIENTED BUSINESS PROCESS MANAGEMENT IN 7S+R ENGINEERING COMPANIES

F. Tkachenko — Mon, 01 Dec 2025 00:00:00 +0200

The article is devoted to the development of a conceptual model of risk-oriented business process management in engineering companies entitled 7S+R, which is based on the classical McKinsey 7S framework and integrates risk management as a cross-cutting element of the organizational system. In today’s dynamic and highly uncertain business environment, engineering companies operate under complicated conditions characterized by high technological complexity of projects, significant investment volumes, multi-level cooperation with subcontractors, and strict regulatory requirements. This leads to the emergence of strategic, operational, financial, human resource, and project risks that directly affect the stability and performance of business processes.

Existing risk management frameworks, including ISO 31000, COSO ERM, and PMBOK, establish general principles and logic of risk management. However, they do not provide sufficient granularity at the level of specific organizational elements and do not allow for the identification of risk sources within the structure of business processes. At the same time, the McKinsey 7S model, which is widely used for organizational diagnostics, focuses on internal organizational alignment but does not explicitly incorporate risks as a systemic management factor.

The proposed 7S+R model addresses this gap by integrating the Risk component into all seven organizational elements - strategy, structure, systems, shared values, management style, staff, and skills. Risk is treated not as a separate management object, but as a multidimensional characteristic that permeates each element of the model and determines its resilience to internal and external threats. This approach makes it possible to move from fragmented risk management toward a comprehensive risk-oriented architecture of business processes.

The practical value of the model lies in its applicability for comprehensive organizational diagnostics, support of strategic and operational managerial decisions, as well as for designing transformation programs and increasing the adaptability of engineering companies in volatile and risk-intensive environments.

MATHEMATICAL MODELING OF HEAT TRANSFER IN THE WORKING ZONE OF A FLOUR MILL ROLLER

O. Burnaiev , V. Semerak , О. Ponomarenko, І. Horodetskyi , O. Lysa — Mon, 01 Dec 2025 00:00:00 +0200

The article presents an extended analytical and numerical study of heat transfer processes occurring in the working zone of a flour milling roller, where intensive and spatially non-uniform heat generation arises during the interaction between the grain mass and the metallic roller surface. It is demonstrated that heat produced by friction, plastic deformation, and partial fracture of grain accumulates within the contact region and strongly determines the temperature rise on the roller surface, ultimately influencing product quality. Based on Jaeger’s classical theory of moving heat sources, an analytical model is developed to describe the temperature distribution in dimensionless coordinates, enabling the application of the results to rollers of various sizes and structural configurations. The influence of the Peclet number, thermal conductivity, geometric characteristics of the contact zone, and heat flux intensity on the formation of the temperature field is analyzed in detail. The study shows that the maximum temperature occurs near the trailing edge of the contact zone, where the cumulative thermal effect is the strongest. Increasing the Peclet number reduces the peak temperature, yet considerably extends the downstream heated region, reflecting a shift in the balance between heat diffusion and roller surface velocity. Numerical simulations based on double integration of the heat-release distribution validate the analytical model across a wide range of milling regimes. The effectiveness of internal liquid cooling is investigated, revealing that it reduces the average temperature but provides only limited mitigation of local overheating within the contact area. Several strategies for improving thermal management are proposed, including pre-cooling of the grain, optimization of rotational parameters, and the use of localized high-intensity cooling methods. The results obtained contribute to improving the thermal stability, operational efficiency, and product quality in roller milling systems.

MATHEMATICAL MODELING OF HEAT TRANSFER PROCESSES IN THE FRICTION ZONE OF ROUGH SURFACES

М. Semerak , V. Semerak , Т. Bubniak, О. Burnaiev , О. Ponomarenko, О. Hovda — Mon, 01 Dec 2025 00:00:00 +0200

The paper presents an analytical study of transient heat transfer processes occurring in the frictional contact zone of rough solid bodies with a circular contour contact area. The mathematical model combines the heat conduction equation for a half-space with a modified contact interaction law that accounts for the real micro-geometry of the surface through the roughness parameter β. It is shown that the value of β determines the size of the contour contact region and significantly affects the actual pressure distribution, which, for rough surfaces, differs markedly from the classical Hertz solution. A quasi-Hertzian pressure profile is employed to accurately describe the increase in real contact area under low loads and elevated roughness levels.

To solve the transient problem, the Hankel and Laplace integral transforms are applied, yielding an analytical expression for the temperature field at any point within the half-space. Based on the obtained formulas, a numerical analysis of the influence of the roughness parameter β, the pressure distribution, and the frictional heat flux on the peak temperature and its spatial distribution is conducted. It is established that an increase in β leads to a decrease in the maximum temperature in the contact center due to the enlargement of the contour contact area and the corresponding redistribution of thermal energy.

The results demonstrate good agreement with published analytical and experimental findings by other authors concerning the influence of surface micro-geometry on frictional heating. The proposed model can be applied to the thermal assessment of frictional components such as disc brakes, clutches, sliding and rolling bearings. The approach improves the accuracy of predicting temperature peaks, which is crucial for enhancing the reliability and durability of tribological systems.

MATHEMATICAL MODELING OF THE THERMOELASTIC STATE OF AN ISOTROPIC HALF-SPACE UNDER THE INFLUENCE OF A FRICTIONAL HEAT SOURCE

V. Semerak, М. Semerak — Mon, 01 Dec 2025 00:00:00 +0200

This paper presents an analytical study of the thermoelastic state of an isotropic half-space subjected to a frictional heat source acting on its boundary surface. The relevance of this research stems from the need to enhance the accuracy of stress-strain assessments for machine components and structural elements that operate under intense frictional contact and substantial thermal loads. Examples include braking systems, bearing units, and frictional assemblies. The nonuniform temperature distribution caused by frictional heating leads to high thermal gradients and the formation of a complex thermoelastic stress state in the near-surface region of the material.

The aim of the study is to derive analytical expressions for the components of the thermal stress tensor in an isotropic half-space, while taking into account thermocontact conditions. Additionally, it analyzes the influence of surface roughness on the level of equivalent stresses. The investigation is conducted within the framework of classical thermoelasticity, based on the assumptions of no body forces, internal heat sources, or external mechanical loads. The axisymmetric thermoelastic state is described using the thermoelastic displacement potential and the Lame stress function.

To solve the formulated boundary-value problem, Hankel and Laplace integral transforms are employed. This approach enables the derivation of closed-form analytical expressions for the thermal stress components and ensures that the boundary conditions on the half-space surface are satisfied exactly. A dimensionless thermocontact parameter is introduced to characterize the thermal contact conditions and surface roughness at the friction interface. It is demonstrated that this parameter significantly affects the distribution and magnitude of thermal stresses in the near-surface zone.

To quantitatively assess the intensity of the thermoelastic state, the Huber-Mises-Hencky energy criterion is utilized. Numerical analysis of the obtained analytical solutions is conducted, and the results are presented as graphical representations of equivalent stresses along the depth of the half-space. The analysis reveals that an increase in the surface roughness parameter leads to a decrease in the overall level of thermal stresses. However, a local maximum of equivalent stress persists at the friction surface.

The scientific novelty of this work lies in the analytical integration of the thermocontact criterion into the study of the thermoelastic state of an isotropic half-space. The practical significance of the results lies in their applicability to the engineering analysis and design of thermally loaded friction components, thereby enhancing their strength and durability.

MATHEMATICAL MODEL FOR RESEARCHING THE STABILITY OF ROAD TRAINS DURING BRAKING MODES

P. Prohnii, V. Shevchuk , P. Popovych, R. Rozum, M. Buriak, А. Papinko — Mon, 01 Dec 2025 00:00:00 +0200

The article analyzes the braking dynamics of two-link articulated road trains. This is because two-link road trains have become widespread and form the basis of the vehicle fleets of most logistics companies in Ukraine and abroad. For their maximum efficient use, it is necessary to ensure compliance with the main operational properties that determine traffic safety. Improvement of the operational characteristics of road trains is achieved through a comprehensive study of real operating conditions and consideration of changes occurring in vehicle systems under the influence of operating factors. At the same time, significant attention must be paid to changes occurring in the running gear and braking systems of road trains, since changes in the geometric characteristics of the chassis directly affect their force, kinematic, and stiffness properties. The presence of axle misalignment in road trains leads to changes in the distribution of reaction forces at the tire–road contact patches. As a result, the braking characteristics of road trains change, which directly depend on the nature of wheel–road interaction and may cause a deterioration in vehicle stability. The study investigates two-link semi-trailer combinations consisting of a two-axle tractor and a three-axle semi-trailer equipped with non-steering axles. The equations of motion for the road train during braking modes, which consider the axle installation angles of the semi-trailer and the magnitude of braking forces acting on the wheels of the trailer unit, enable the determination of wheel deviation angles and kinematic parameters essential for solving the system of differential equations.

RELIABILITY AND TECHNICAL MAINTENANCE OF MACHINES

О. Zachek , A.-V. Midyk , О. Lysa, V. Ptashnyk — Mon, 01 Dec 2025 00:00:00 +0200

The paper presents the design, software implementation, and modeling of a digital clock-thermometer based on the Arduino Micro (ATmega32U4) platform with indication on 4×8×8 (FC-16) LED matrix modules driven by MAX7219 chips. The device provides real-time display of the current date and time (RTC DS1307), temperature in °C/°F (LM35DZ sensor), clock and temperature format settings, text scrolling, and brightness control. The hardware schematic was developed in Proteus VSM, along with algorithms and key software modules (RTC, MAX7219 display, LM35 thermometer). Simulation in Proteus ISIS and testing of a physical prototype confirmed the correct operation of the system. Measurement accuracy, display modes, energy efficiency, EMC aspects, and scalability were analyzed. The digital device is based on the Arduino Micro platform with an AVR ATmega32U4 microcontroller, interfaced with a DS1307 real-time clock, a precision LM35DZ temperature sensor, and an 8×32 FC-16 LED matrix display module consisting of four 8×8 matrices with MAX7219 drivers. The microcontroller reads date and time from the RTC DS1307, the ambient temperature from the LM35DZ sensor, and outputs this information to the LED matrix display. The device supports adjustment of current time, date, and display parameters. The work includes the development of the circuit schematic and the digital clock-thermometer model using Proteus CAD tools. The software and algorithms were implemented in the Arduino IDE. Simulation in Proteus ISIS and prototype testing confirmed system functionality.

The results demonstrate the feasibility of using MAX7219 drivers for matrix display control with minimal I/O lines and highlight the potential of this approach for household and educational measuring devices. Future research should focus on integrating additional sensors (humidity, pressure), implementing wireless time synchronization, and optimizing power consumption.

THEORETICAL STUDIES ON THE INFLUENCE OF KINEMATICS ON THE WORKFLOW OF A CRANKLESS ENGINE

Т. Kolesnikova , О. Lykhodii , Т. Makhorkina, М. Boiko — Mon, 01 Dec 2025 00:00:00 +0200

Modern requirements for internal combustion engines focus on increasing efficiency, reducing specific fuel consumption, and lowering the level of toxic emissions. One promising direction of development is the use of connecting-rod-free mechanisms, whose kinematic features can significantly influence the engine’s performance. Specifically, the absence of a traditional connecting-rod transmission alters the piston motion, the character of dwelling at the top and bottom dead centers, the magnitude of side forces, and the level of mechanical friction losses. This opens up opportunities to decrease energy losses, improve gas-exchange conditions, and achieve more complete combustion of the fuel–air mixture.

The article presents an analysis of the kinematic and dynamic characteristics of various designs of crankless engines. Theoretical studies demonstrate that changes in the piston trajectory, as well as the profiles of velocity and acceleration, impact heat release and the indicator parameters of the cycle. A comparative analysis with classical crank-slider mechanisms confirms that the elimination of side forces leads to reduced specific mechanical losses and vibrational loads, along with a potential increase in power output and thermal efficiency.

Additionally, it is important to note that the efficiency of connecting-rod-free mechanisms largely depends on the manufacturing accuracy and synchronization of moving components, as well as on the choice of materials that provide the required stiffness and wear resistance under increased loads. Another critical aspect is the optimization of geometric parameters of the piston-motion profile to achieve the desired thermodynamic characteristics across a wide range of operating conditions. Aligning the kinematics of the drive with the processes of mixture formation and combustion can lead to a more uniform pressure field in the cylinder and a reduction of local thermal stresses in the combustion chamber components. These advancements create opportunities for the development of advanced power units that can combine high efficiency, reliability, and environmental safety.

The obtained results indicate the feasibility of further studies of connecting-rod-free kinematic schemes as a basis for creating new generations of engines with improved energy and environmental performance. It is recommended to give special attention to experimental validation of theoretical models, assessment of actual mechanical losses, and durability of drive components.

ANALYSIS OF METHODS FOR ASSESSING THE STRENGTH OF STRUCTURAL MATERIALS OF WORKING ELEMENTS OF GRINDING MACHINES IN TERMS OF CRACK RESISTANCE

V. Burtak , Т. Kоkhana , R. Barabash — Mon, 01 Dec 2025 00:00:00 +0200

This text provides a concise review of the components of grinding machines and the primary methods of grain grinding. It discusses the factors that contribute to the wear and failure of these components. Additionally, it outlines methods for assessing the strength of structural materials and their welded joints using beam specimens with a lateral crack, evaluated under cantilever and three-point loading conditions according to the crack resistance criterion (CR).

An analysis of the methods of cantilever bending of a beam with a lateral concentrator at the stage of fatigue crack initiation under an asymmetric cycle is carried out under the condition of cantilever bending of a beam specimen with a lateral concentrator, or three-point bending of such a specimen with a lateral concentrator in the seam, which is installed in the base and fastening unit. The value of K₁ is obtained in the case of arbitrary e and a constant force P, respectively. It can be used to determine the functional characteristic of crack resistance K_1s according to the described scheme of cantilever deformation of a beam with a lateral crack near the pinch point.

The strength of butt welded joints was assessed, and the schemes of three-point bending of a beam specimen with a lateral crack in the metal of the vertical weld of the butt welded joint were considered according to the strength criterion K_1c. The determination of K_1c of the weld metal of the welded joint was carried out when this weld and the crack in it are perpendicular to the base of the beam specimen.

Analysis of the proposed methods for determining the SIF according to the schemes of cantilever and three-point bending of beam specimens with a lateral crack in the material of the base of the specimen or the weld of the welded joint, respectively, are effective tools for ranking the strength of structural materials and their welded joints in the manufacture of parts of the working elements of grinding machines.

MATHEMATICAL MODELING OF THE STRAINED STATE IN BROAD PIVOTS WITH TWO CIRCULAR HOLES BY CROOK

O. Ponomarenko, О. Burnaiev , V. Semerak, O. Havryliak — Mon, 01 Dec 2025 00:00:00 +0200

It has been observed that elastic components, such as thin plates, are widely used in the design of structures and machines across aviation, shipbuilding, and mechanical engineering. However, these parts are often weakened by various holes for several reasons. When such components are subjected to loading, stress concentrations tend to occur near the holes, which can negatively impact their strength. The distribution of stresses around the edges of the holes is uneven, leading to small areas that experience significantly high stresses. It is in these places that brittle cracks or plastic deformations can develop, potentially resulting in structural failure.

Studying the distribution of stresses near curved holes is crucial from both theoretical and engineering perspectives.

This work presents a solution to the problem of stress concentration in broad pivots featuring two unequal circular holes by crook. The solution is based on a fundamental stress function associated with the stress state in a rod that does not have any holes, to which a second biharmonic function is added. This additional function represents the stress state that arises due to the presence of the holes. The challenge lies in determining the biharmonic stress function that satisfies the boundary conditions at the contours of the holes and extends out to infinity. The scientific novelty of this work is that it provides insights into how the orientation of holes relative to the field of crook loads influences stress concentration. The solution is presented in bipolar coordinates, and formulas for the stresses along the contours of the holes are derived. Additionally, the known result for the displacement of a crook pivots with a single circular hole is included. The obtained stress values along the contours of the holes for certain special cases are also reported.

The findings of this study enable the theoretical determination of the stress concentration factor near the holes and can be effectively applied in engineering practice when designing components in shipbuilding, aircraft construction, and mechanical engineering.

STUDY OF THE SYNERGISTIC EFFECT WHEN SETTING UP AN INVERTER-TYPE WELDING CURRENT SOURCE WITH MICROPROCESSOR CONTROL USING THE EXAMPLE OF THE TPS 2700SMT WELDING MACHINE

О. Shvets, P. Koruniak , S. Berezovetskyi , І. Horodetskyi , R. Sheremeta — Mon, 01 Dec 2025 00:00:00 +0200

Inverter-type welding power sources equipped with microprocessor control can facilitate mechanized and automatic welding processes. Modern semi-automatic welding machines are designed to offer synergistic control, which utilizes microprocessor systems (microcontrollers) to select and ensure optimal values for pulse parameters and the type of welding current. This is achieved while considering factors such as the brand, thickness, and properties of the metal being welded, as well as the characteristics of the welding materials, including the diameter and brand of wire and the type and composition of shielding gas. The synergistic effect allows the user to adjust all settings of the welding machine by changing only one parameter of the welding process. However, the information provided in the operating instructions often does not enable the operator to quickly prepare the machine for use. By studying the specific settings for each available welding process, it is possible to develop a clear algorithm detailing the sequence and limits for adjusting the parameters of the power source, along with practical recommendations for preparing it for work.

Experimental studies were conducted to assess the influence of synergism on the parameters of the MIG/MAG welding process. The research focused on the functional capabilities of the TPS 2700 CMT semi-automatic machine across various modes, including Standard, Synergic, Pulse Synergic, and Cold Metal Transfer. Additionally, the study examined how welding process parameters affect the quality of welds.

Through this investigation, the specific features of setting up each available welding process were analyzed, and the influence of synergism on the adjustment of necessary welding source parameters was assessed. The limits for adjusting these parameters were established, and relationships were defined showing how the parameters of the welding source impact the efficiency and quality of the welding process. It was found that the values of welding current, wire feed speed, and welding voltage are closely related to the thickness of the welded parts and the diameter of the wire. These relationships exhibit different characteristics for various welding modes. Furthermore, the studied parameters significantly influence the shape and dimensions of the welds.

COMPARATIVE ANALYSIS OF EQUIVALENT CIRCUIT MODELS FOR BOUNDARY CONDITION IDENTIFICATION IN THE WAVE EQUATION OF A LONG TRANSMISSION LINE

V. Levoniuk , D. Hrechyn , T. Mykhailovych — Mon, 01 Dec 2025 00:00:00 +0200

This paper proposes a methodology for identifying boundary conditions for the wave equation of a long transmission line, based on the use of equivalent circuits for the terminal discrete sections of the line. The main focus is made to the comparative analysis of three types of substitution schemes – Γ-, T-, and π-equivalent circuits – in order to investigate how their topology and symmetry affect the accuracy of numerical modeling of transient electromagnetic processes in lines with distributed parameters. The mathematical model is built upon the wave (telegraph) equation with second-order partial derivatives, which describes the dynamics of voltage and current along the line. Neumann and Robin–Poincaré boundary conditions are shaped analytically by incorporating the parameters of the equivalent circuits. Particular attention is given to the asymmetry arising from the use of the Γ-scheme. It is demonstrated that this scheme disrupts wave superposition, resulting in outcomes that vary depending on the direction of line energization. In contrast, the T- and π-schemes ensure symmetric loading of the model, leading to stable computational outcomes. Numerical experiments carried out in Intel Visual Fortran Compiler confirm the presence of systematic errors in the Γ-scheme and the accuracy of the T- and π-schemes. The scientific novelty lies in the first-time proposal of a boundary condition identification approach for the wave equation based on equivalent curcuit with symmetry evaluation and accuracy analysis. The proposed methodology is universal and can be applied to the modelling of high-voltage transmission lines operating under both direct and alternating current, which enhances its scientific and engineering value. The presented approach makes it possible to improve the performance of existing electromagnetic simulation tools by ensuring higher computational stability and consistent boundary-condition formulation under complex operating regimes.

JUSTIFICATION OF THE CHARACTERISTICS OF DIAGNOSING OPERATIONAL INDICATORS OF TURBINE GENERATOR STANDOFF BEARINGS

Ya. Marushchak , І. Drobot , D. Hrechyn — Mon, 01 Dec 2025 00:00:00 +0200

A significant amount of research has focused on detecting and eliminating malfunctions in powerful turbogenerators (TG). One important aspect to consider is the impact of standoff bearings on the effective operation of the TG. Failures in these bearings are responsible for a substantial number of rotor accidents. Therefore, this work analyzes the information support necessary for diagnosing standoff bearings, which will aid in assessing their condition before any emergencies arise.

It is known that grease is supplied to the standoff bearings under pressure. During the operation of the TG, metal inclusions can enter the bearing grease, indicating deterioration in the surface condition of the bearing liners. Additionally, any alterations to the design of the TG bearing assembly may also be reflected by an increase in vibration. This vibration can provide further insight into the assembly's condition.

By examining the design features of TG bearings and the physical processes at play, we can deduce that information regarding the presence of metal inclusions in the lubricant, alongside the vibration levels of the TG standoff bearing, can be used to assess its condition. However, there is currently no objective assessment, in numerical form, demonstrating that these two diagnostic features are indeed effective for evaluating the state of TG standoff bearings.

This work aims to justify the information support for the procedure used to diagnose the condition of TG bearing assemblies. This can be achieved by calculating the amount of information that reflects the relationship between the chosen diagnostic features and the technical condition of the TG standoff bearings.

The information derived from inspections of the lubricant and vibration of the TG bearing stands indicates that both diagnostic features are informative concerning their condition. Notably, high levels of information regarding the inoperable state of the standoff bearings are obtained when inspections focus on these two parameters. Thus, it is the objective confirmation of the recommendation to inspect TG standoff bearings based on the condition of the lubricant and the magnitude of the housing vibration, represented in numerical terms.

COMPARATIVE ANALYSIS OF THE METHODS FOR IMPLEMENTING FRACTIONAL-ORDER INTEGRATOR-DIFFERENTIATOR CONTROLLERS

Ya. Marushchak , І. Drobot, D. Hrechyn — Mon, 01 Dec 2025 00:00:00 +0200

At the present stage, the NINTEGER package is used for modeling fractional differential and integral elements in electromechanical systems. The application of the specially developed NINTEGER package as an add-on for the MATLAB Simulink package has enabled the first studies in the field of using fractional-order controllers in fractional-order automatic control systems. However, it has certain drawbacks: the NINTEGER package works exclusively in the MATLAB Simulink environment and cannot be used outside this package. The literature does not clarify the accuracy of representing fractional elements and fractional-order PID controllers in this package.

The work presents a comparative analysis of mathematical models based on the well-known Oustaloup transformation in the MATLAB programming environment with the possibility of its use in MATLAB Simulink instead of the NINTEGER application. In addition, a study was conducted on the accuracy of integral and differential regulators of fractional order represented in the Oustaloup, Riemann, Riemann-Liouville, and Grünwald-Letnikov forms compared to the model obtained through the Laplace transformation as a benchmark. Based on the conducted analysis, it is concluded that the models built on the Oustaloup transformation are the most promising for the implementation of regulators. Oustaloup models allow replacing fractional order transfer functions with equivalent transfer functions of integer order. This provides significantly higher performance in processing control influences compared to Grünwald-Letnikov models. Regarding accuracy, it is somewhat worse, but this drawback is compensated for by the simplicity of the computational procedure.

SELECTING THE TYPE OF ELECTRIC DRIVE FOR A MECHANISM WITH SYSTEMATIC UNDERLOADING

D. Hrechyn , I. Drobot , М. Hoshko , R. Levus — Mon, 01 Dec 2025 00:00:00 +0200

The paper discusses the design and operation of a feed grinder and the control scheme of an automated electric drive system. In modern operational conditions, many enterprises face power outages and utilize backup power sources with limited capacity. Given the livestock industry's constant need for feed availability, it sometimes becomes necessary to perform grinding operations while relying on these backup power sources. To facilitate the operation of the backup power source, it is possible to reduce the load on the grinder. The paper also analyzes other types of grinders, along with their structures and control schemes for automated electric drive systems. A proposal is made to upgrade the electric drive by replacing the on-off control of the asynchronous motor with smooth load control, achieved through frequency control of the motor's rotation speed. Additionally, to ensure the grinder operates effectively with a backup power source, it is recommended to connect the main motor to a reduced voltage by configuring the windings in a "star" circuit.

The work describes a developed model of the proposed automated electric drive system for a grinder, which includes an automated feeding mechanism based on a frequency converter. Research was conducted to evaluate its performance in both nominal operating mode and when supplied with reduced voltage according to the "star" configuration and a lower task signal. The graphical representations of transient processes during load changes demonstrated a high response speed of the automated electric drive system, which enables efficient performance.

The technological benefits of increased grinder productivity in nominal mode are attributed to this rapid response, allowing the electric drive to handle its nominal load effectively, as the automatic control system can quickly manage overload situations. Furthermore, the system ensures the grinder operates smoothly despite contemporary power supply challenges, particularly when running off a limited power source.

RESEARCH ON THE CHARACTERISTICS OF LED LIGHT SOURCES

М. Hoshko , T. Goshko, І. Drobot — Mon, 01 Dec 2025 00:00:00 +0200

Advances in semiconductor physics, optics, and optoelectronics over the past 10 to 15 years have enabled the development of light sources that are 4 to 10 times more energy-efficient and have a lifespan 30 to 100 times longer than traditional incandescent lamps. One significant type of these light sources is solid-state LEDs. Recently, numerous articles have been published in lighting journals discussing the advantages of LEDs and predicting their future developments. However, our extensive research has indicated that, in many cases, the performance characteristics claimed by manufacturers do not match the actual values. This led us to investigate the true characteristics of LED lamps currently available on the Ukrainian market, to identify the most effective options.

This study focuses on the characteristics of modern light sources, using LED lamps as an example. We examined several brands, including LED A60 10W, IEK A60 11W, Horoz Electric 10W, Eurolamp 9W, HOPFEN 10W, TECHLAMP 10W, Emilight 11W, OSRAM 10.5W, LEBRON LED 10W, and Light Master 11W, to evaluate their compliance with declared lighting and electrical parameters. The analysis was conducted using products available in the Lviv market as of June 2025.

The experiments took place at the Department of Electrical Engineering Systems within the Electric Lighting Laboratory.

Several parameters were investigated, including illumination levels based on the supply voltage, the pulsation levels of the LED lamps in relation to the supply voltage, the temperature conditions of the lamps with regard to the supply voltage, power consumption relative to the supply voltage, and the light output of the LED lamps concerning the supply voltage.

Following the experiments, we analyzed the results according to the above parameters and formulated conclusions and recommendations based on our findings.

ASSESSMENT OF ELECTRIC VEHICLES SUITABILITY FOR LOCAL OPERATION BASED ON THE INTEGRAL INDICATOR

S. Khimka , O. Sukach , M. Mahats , Yu. Habrіiel , I. Dufanets, T. Melnykov — Mon, 01 Dec 2025 00:00:00 +0200

This article addresses the important scientific and practical issue of selecting the optimal electric vehicle (EV) model for use in the specific conditions of urban agglomerations in Ukraine. The current trends in the transport market show a rapid increase in interest in "clean" technologies. However, this growth is hindered by inadequate charging infrastructure, unstable power supply, and the limited financial means of most consumers. Therefore, there is an urgent need to develop a scientifically grounded approach for comprehensively assessing vehicle suitability, particularly for local short-distance trips. During the research, a thorough analysis of contemporary scientific literature and statistical data regarding the dynamics of the EV market was conducted. This analysis allowed for the identification of key criteria that shape consumer priorities. Unlike existing approaches that often emphasize maximum technical specifications, this paper proposes an enhanced system of evaluation criteria. In addition to standard technical indicators (such as range, charging power, and reliability) and economic indicators (such as purchase cost and maintenance costs), the parameter of "energy efficiency" (specific energy consumption measured in kWh/100 km) is incorporated. This inclusion enables more accurate forecasting of operational costs. The scientific novelty of this study lies in the development of a comprehensive multi-criteria assessment methodology. This methodology uses weighting coefficients to reflect the significance of each criterion, tailored to the realities of urban operation in Ukraine, and applies the linear scaling method (min-max) for normalizing diverse parameters. This approach allows for the consolidation of cost, technical, and ergonomic indicators into a single dimensionless evaluation scale. The distribution of weight coefficients was carefully justified, with financial affordability assigned the highest priority (0.25), while energy efficiency and operational costs each received significant weights (0.15). The range for urban cycle was considered a secondary factor (0.15). The methodology was tested using six of the most popular models available on the Ukrainian market: Nissan Leaf, Renault Zoe, Hyundai Kona Electric, Volkswagen e-Golf, Tesla Model 3, and Tesla Model Y. The calculation of the integral suitability indicator revealed that for short-distance use, compact models performed better. Renault Zoe (integral indicator of 7.95) and Hyundai Kona Electric (7.90) ranked the highest, providing an optimal balance of initial investments, operational costs, and functionality. In contrast, more technologically advanced Tesla models received lower ratings (ranging from 7.70 to 7.80) primarily due to their high costs, which are a critical concern for the average consumer. Additionally, sensitivity analysis indicated that in a scenario of rising electricity tariffs, the competitive advantage shifts toward models with the highest energy efficiency, such as the Hyundai Kona Electric. The practical significance of these results lies in the creation of a universal toolkit designed to optimize the selection of vehicles for both individual users and corporate fleets, aiming to minimize the total cost of ownership.

WIND TURBINES AND FARMS USING AI FOR ENERGY STORAGE

P. Radek, G. Wałowski, S. Syrotyuk, V. Halchak , T. Stanytskyy , H. Syrotyuk — Mon, 01 Dec 2025 00:00:00 +0200

The article provides a comprehensive overview of wind turbine technologies, including both onshore and offshore systems, focusing on aspects such as grid integration, trends in the levelized cost of energy (LCOE), and applications of artificial intelligence (AI) in areas like forecasting, diagnostics, control, and digital twins from 2015 to 2025. The importance of energy storage solutions, such as battery energy storage system (BESS), liquid air energy storage (LAES), compressed air energy storage (CAES), power-to-x/H₂ (P2X/H₂), and pumped storage, is also discussed in relation to enhancing system flexibility and increasing the market value of wind energy. The text identifies research gaps and priorities for research and development. Wind energy remains cost-competitive, with onshore wind continuing to be among the lowest cost options for new energy capacity (weighted LCOE ≈ $0.034/kWh globally). Cost variations are mainly influenced by capacity factor (CF), the weighted average cost of capital (WACC), and execution risks. The scale of capacity and maturity of the supply chain are improving, particularly for offshore wind (12–20+ MW/turbine). However, costs and timelines are sensitive to logistics, weather conditions, and the availability of installation vessels. High-voltage direct current (HVDC) technology is becoming the standard for exporting offshore power, and transitioning to meshed/multi-terminal systems require interoperability across different vendors (InterOPERA) and standardized FAT/SAT/HIL testing. Ensuring grid-forming capabilities and converter compatibility is essential for the stability of low-inertia power systems, necessitating harmonized testing profiles and certification requirements at the wind turbine generator (WTG)/wind power plant (WPP)/HVDC levels. Artificial intelligence is increasingly being utilized in operations, achieving optimal results by combining forecasting methods (long short-term memory networks (LSTM)/ gated recurrent units (GRU)/Transformers) with fault detection and diagnosis (FDD)/ remaining useful life (RUL) predictions and wake steering techniques. These results are measured not only by the change in annual energy production but also by their impact on service profiles and network constraints.

Current and evolving ENTSO-E requirements include fault ride-through capabilities (low-voltage ride-through (LVRT) and high-voltage ride-through (HVRT)), active power (P) and reactive power (Q) control (Volt-VAR/Volt-Watt), ramp-rate constraints, primary and secondary frequency control (FCR/FRR), as well as limits on harmonics, flicker, and distortion. Converter-based generation units must ensure low short-circuit power (weak grid) and during disturbances, highlighting the increasing significance of dynamic models (root-mean-square simulation (RMS)/electromagnetic transient simulation (EMT)) and compliance validation during both commissioning and operation.

MATHEMATICAL MODELING OF SOIL MOISTURE CHANGES CONSIDERING IMPULSE EFFECTS IN DIGITAL AGRICULTURE

Mon, 01 Dec 2025 00:00:00 +0200

One of the key topics requiring attention within the framework of precision agriculture is soil moisture control. This parameter directly affects crop yield levels, the efficiency of water resource utilization, and the overall condition of the agroecosystem. Insufficient moisture can significantly reduce yield, while excessive moisture can cause nutrient leaching and even soil erosion. Therefore, it is crucial to understand how soil moisture changes under the influence of various factors, such as precipitation, evaporation, infiltration, and plant uptake. To improve agricultural practices, it is important to develop effective mathematical models that facilitate the analysis of soil moisture dynamics. This, in turn, will enable accurate determination of the need for additional irrigation at optimal times.

The aim of this work is to form a mathematical model of changes in soil moisture dynamics taking into account irrigation in the form of pulse action, which allows to establish optimal time for irrigation, and therefore - to increase the efficiency of water use in precision agriculture. Methodology and results consist in the application of a differential equation with pulse action to consider pulse irrigation under the conditions of achieving the required level of drainage (i.e. dehumidification). The time points of reaching critical moisture levels that require the introduction of an irrigation pulse have been determined (for samples of different types of soils). The model presented in the work can be used for automated control of irrigation systems, assessment of the efficiency of moisture retention in different types of soils, as well as for optimization of agrotechnical measures in precision agriculture. Scientific novelty and practical significance lie in the proposed pulse mathematical model of moisture dynamics, which allows to accurately formalize the moments of necessary irrigation. The results can be used to create automated irrigation control systems in precision agriculture, reducing water waste and increasing yields.

TECHNOLOGY FOR WASHING AGRICULTURAL MACHINERY AND A METHOD FOR EVALUATING ITS EFFECTIVENESS AT DIFFERENT LEVELS OF CONTAMINATION

А. Tryhuba , О. Filkin — Mon, 01 Dec 2025 00:00:00 +0200

An analysis of existing technologies and approaches to washing agricultural machinery has been carried out. It has been established that, despite their prevalence, they focus mainly on individual performance indicators and do not take into account the complex impact of time, energy consumption, and the quality of wash water. The feasibility of improving the technology for washing agricultural machinery and developing a method that allows for an objective assessment of the process effectiveness at different levels of contamination has been substantiated. The improved technology for washing agricultural machinery is based on a combination of traditional operations with modern intelligent approaches to quality control. The algorithm of this technology includes 18 steps that ensure the use of machine vision for the initial assessment of the level of contamination and the adaptation of the sequence of operations to the actual condition of the surfaces. Additional washing is provided to remove difficult stains and re-control after basic cleaning, which forms a closed cycle of the process, taking into account sensor data, reducing resource consumption and improving environmental safety. The developed method for evaluating washing efficiency consists of six blocks and provides a comprehensive approach to performance analysis, combining surface cleaning criteria, wash water quality, operation duration, and resource consumption into an integrated index. This allows for an objective comparison of washing modes, taking into account technological and economic aspects, and forms the basis for the implementation of automated control systems. As a result of the research, the washing efficiency of a John Deere 6130R tractor with a Horsch Pronto 6 DC trailer seed drill was evaluated at three levels of contamination. It was found that at a low level, the integral efficiency index reached the highest values due to the optimal ratio of cleaning quality and resource consumption. At the same time, at a high level of contamination, the key factors reducing efficiency are excessive water and energy consumption, as well as increased cycle duration. Further research should be focused on the development of adaptive cyber-physical washing systems capable of optimizing operating modes in real time, taking into account the actual level of contamination, resource consumption, and environmental requirements.

AGROECOLOGICAL ASSESSMENT OF MACHINE-TRACTOR UNITS BASED ON WES METODOLOGY

L. Krainyk , P. Syvulka — Mon, 01 Dec 2025 00:00:00 +0200

The increasing use of heavy machine-tractor units (MTUs) is exacerbating the issue of excessive soil compaction in agricultural land. This highlights the urgent need for a rapid and reliable assessment of their agro-environmental performance, particularly with the advancements in terramechanics theory and instrumentation. The complexity and lengthy processes involved in evaluating the impact of MTUs on soil compaction, guided by regulatory standards established over thirty years ago, underscore the necessity for revising these methodologies. A modern approach to assessing the physical and mechanical properties of soil as a load-bearing surface, along with its interaction with MTUs, is essential.

In this context, special attention should be given to the WES methodology, developed by the U.S. Army Corps of Engineers. This approach has become a benchmark for NATO countries in characterizing soil and off-road properties, as well as in determining the cross-country mobility of ground vehicles. The WES methodology is based on the operational assessment of soil strength using a standardized cone penetrometer, which produces the Cone Index (CI). This is combined with a validated computational framework that predicts the passability and mobility of wheeled and tracked vehicles over unpaved terrain. Additionally, it considers secondary compaction caused by the wheels of successive axles, variations in tire inflation pressure, and other machine-specific parameters. For agricultural machinery, it is also important to consider variations in the dimensions of the front and rear wheels, as well as the dynamic redistribution of axle loads during soil tillage operations. Experimental studies using the Fendt 1038 Vario tractor, with different wheel sizes on the front and rear axles, have been conducted. These studies measured soil hardness based on the Cone Index (CI) system and tire-soil contact patches. The results revealed a strong correlation between soil hardness and soil density. A review and analysis of additional field studies containing hardness and density data for various soil types further confirmed this correlation. This information allows for proposing necessary amendments to the existing regulatory framework for the agroecological assessment of agricultural machine-tractor units, significantly accelerating the evaluation of soil physical and mechanical properties.

HYBRID DRIVE OF THE «MAMAI-2» CARGO-PASSENGER OFF-ROAD VEHICLE

А. Kikhtan , D. Nalesnyk — Mon, 01 Dec 2025 00:00:00 +0200

Based on the conducted review and analysis of hybrid drive system designs for off-road vehicles, primarily military ones, which have recently begun to appear in the advanced NATO armies, and on the generalization of operating conditions for diesel vehicles such as the Mamai buggy used in military operations, a drivetrain layout and the required parameters and characteristics have been developed in cooperation with specialists from PJSC “UkrAvtoBusProm.” These developments correspond to categories M1/N1 of class SG with AF-type bodywork in accordance with EU Directive No. 2018/858.

The fundamental difference from mass-produced hybrid passenger cars and all-wheel-drive crossovers lies in the modification of the drivetrain configuration - transitioning to a series (serial) hybrid scheme - and a tenfold increase in battery capacity to ensure a substantial all-electric range in off-road conditions with the diesel generator disengaged. Considering the diversity of off-road terrains, the issue of differentiated range assessment depending on driving conditions has been examined, along with the subsequent calculation of the required battery capacity and diesel generator power.

Special attention has been given to the additional protection of the battery and electric drive components under conditions involving swamps and water obstacles. General aspects of vehicle layout for off-road applications have also been analyzed, including the suspension system as a key determinant of mobility (speed regimes) constrained by maximum permissible vibration accelerations, the formation of the transmission gear ratio range, and the selection of appropriate tire sizes.

Building on the development of the diesel-powered Mamai buggy, an aggregate configuration has been elaborated for an operational mass of up to 2 tonnes, along with an evaluation of the potential driving range, including the possibility of using components from widely available Nissan Leaf and Toyota Prius vehicles (considering wartime conditions and the correspondingly limited service life).

EXPERIMENTAL STUDIES OF THE INFLUENCE OF SEPARATE TIRE PRESSURE REGULATION ON THE BEARING MOBILITY PARAMETERS OF AUTOMOTIVE VEHICLES

V. Khoma — Mon, 01 Dec 2025 00:00:00 +0200

The article addresses the problem of improving the mobility of off-road wheeled vehicles under operating conditions on non-uniform supporting surfaces characterized by varying rolling resistance and traction levels. It is shown that tire inflation pressure is a key controllable factor determining the efficiency of tire–soil interaction, as it directly affects radial deformation, contact patch area, rut depth, energy losses, and permissible vehicle speed. It is substantiated that the use of centralized tire pressure regulation systems does not allow the full mobility potential to be realized due to different operating conditions of the front and rear axle wheels, which move over soil with varying degrees of compaction.

The study aims to experimentally determine the speed performance of a four-wheel-drive UAZ-469 vehicle at various tire inflation pressures and assess the adequacy of a vehicle motion mathematical model developed in the MATLAB Simulink environment for off-road conditions. Experimental investigations were carried out on a natural sandy off-road test section with a preliminary evaluation of the physical and mechanical properties of the supporting surface using the cone index (CI) determination method in accordance with the WES and MMP standards.

During the tests, measurements of soil cone index, tire inflation pressure, tire radial deformation, maximum vehicle speed, and distance traveled were performed using a synchronized measurement system. The obtained results demonstrated that separate tire pressure regulation provides an increase in the maximum off-road speed by 15–20% compared to centralized regulation, as well as an improvement in mobility indicators according to the WES and MMP methodologies. The research results confirm the feasibility of individual tire pressure selection for each axle as an effective means of enhancing the mobility of wheeled vehicles.