The scientific bulletin of Kherson state maritime academy

Title

Halyna Anatoliivna Vrublevska — Wed, 23 Jul 2025 00:00:00 +0300

COLLECTIVE CYBERSECURITY OF AUTONOMOUS MARITIME VESSELS BASED ON DECENTRALIZED INTELLIGENT ANALYSIS

Y. Kozachok, A. Simanenkov, S. Zinchenko — Wed, 23 Jul 2025 00:00:00 +0300

This paper presents a comprehensive approach to enhancing the collective cybersecurity of autonomous maritime platforms through the integration of intelligent data analysis methods, decentralized coordination mechanisms, and a custom hybrid architecture that combines Long Short-Term Memory (LSTM) neural networks with onboard large language models (LLMs). The core innovation lies in augmenting traditional LSTM-based anomaly detection with LLM-driven semantic interpretation of navigational inconsistencies — a fundamentally novel strategy for self-governing maritime environments.

Particular attention is paid to the detection, explanation, and decentralized coordination of responses to Global Positioning System (GPS) spoofing attacks, which pose a significant threat to navigational accuracy, operational safety, and the overall coherence of fleet activities. The proposed system, built on a proprietary LSTM-LLM configuration, equips each vessel with multi-level cognitive capabilities: real-time anomaly detection, natural language generation of contextual explanations, and autonomous formulation of strategic responses without dependence on centralized oversight or communication infrastructure.

Unlike conventional centralized solutions, the system empowers each vessel to independently analyze situational data, derive human-understandable contextual insights, and adapt its behavior accordingly. The architecture includes a lightweight protocol for structured message exchange in JavaScript Object Notation (JSON) format, enabling efficient, resilient, and secure inter-vessel communication. Additionally, a decentralized consensus mechanism, based on a dynamically updated trust matrix, enhances the fleet’s robustness against partial compromise and improves operational integrity.

The effectiveness of the proposed approach is demonstrated through a simulated GPS spoofing scenario involving one compromised vessel within a five-vessel fleet. The results confirm the system’s ability to detect anomalies accurately, isolate the compromised unit, and successfully adapt the navigational strategies of the remaining vessels — thus maintaining uninterrupted mission continuity despite active cyber disruption.

AUTOMATIC ADJUSTMENT OF THE DYNAMIC POSITIONING SYSTEM REDUNDANT STRUCTURE BY DETERMINANT

S. M. Zinchenko, O. M. Tovstokoryi, P. S. Nosov, D. M. Onyshko, Yu. A. Kozachok — Wed, 23 Jul 2025 00:00:00 +0300

The object of the study is the dynamic positioning processes of a vessel with two stern azipods and a bow thruster. Automation of motion control processes allows to significantly increase the efficiency of control systems by using modern methods of information processing, including optimization, and is used in many industries: space, aviation, marine, welding production, etc. New opportunities for increasing the efficiency of control systems have appeared with the use of redundant control. Redundant structures of actuators have traditionally been used for redundancy and increasing the reliability of control systems by excluding failed devices from operation. Over time, they have also been used to optimize control processes. In the marine industry, redundant structures have become most widespread in dynamic positioning systems. One of the requirements for such systems is to ensure maximum accuracy of positioning processes, including under the influence of external influences from any direction. According to the authors, this ability of the control system can be ensured by maximum dilution of the control vectors of the structure (maximization of the determinant). The paper developed a method for tuning a redundant structure that provides this possibility. The obtained result is explained by: using the on-board computer in the control system; finding the optimal state of the structure at each step of the on-board computer, which is determined by the maximum determinant, taking into account the constraints of the type of equalities, to create the necessary controls by the structure, and the type of inequalities, to take into account the constraints of the structure on the maximum thrust force and the angle of rotation of the screws; reconfiguring the structure to a certain optimal position. The operability and effectiveness of the method are confirmed by mathematical modeling in the MATLAB environment. The modeling results showed that the reconfiguration of the structure can be carried out against the background of the execution of the main functional tasks, without creating disturbing forces and moments. The obtained results are reproducible and can be used in the design of dynamic positioning systems.

INTELLIGENT INFORMATIONMEASUREMENT SYSTEM FOR DIAGNOSTICS AND MONITORING OF A HYBRID MARINE TURBOCHARGER WITH A FUZZY MODEL

Yu. O. Lebedenko, K. V. Tymofeev, S. V. Voronenko, S. V. Bihun — Wed, 23 Jul 2025 00:00:00 +0300

This paper focuses on enhancing the efficiency and reliability of modern marine power units through advanced diagnostic and monitoring systems. It presents an intelligent information-measuring system (IMS) designed for real-time condition monitoring of hybrid marine turbochargers (HMTCs), which integrate exhaust gas recovery with auxiliary electric motor/generator support. Due to their complexity and demanding operational conditions, HMTCs require sophisticated diagnostics. The proposed IMS leverages fuzzy logic for adaptive control and predictive maintenance. The IMS is structured to process multi-parameter data streams from sensors that monitor not only key parameters of the turbo-gas-dynamic components (such as temperature, pressure, rotational speed, vibrations, and lubrication) but also the operational parameters of the electrical machine. Fuzzy logic algorithms enable precise sensor data interpretation, addressing real-world uncertainty and formalizing expert knowledge. The system employs fuzzification, fuzzy inference rules, and defuzzification to generate accurate diagnostic assessments, distinguishing normal operation, potential deviations, and critical faults. With growing industry demands for fuel efficiency and reliability, conventional diagnostics often fail to account for HMTC complexities. The scientific novelty of this research lies in its adaptive diagnostic process using fuzzy logic, which models expert-derived rules for nuanced fault detection. The IMS aids in optimizing control parameters, regulating supercharging, and activating emergency systems, thereby improving early fault detection. This IMS has significant maritime applications, particularly for vessels with hybrid turbocharging. By supporting condition-based maintenance, it reduces downtime and enhances operational efficiency. Its ability to ensure reliable engine performance promotes safer maritime operations and contributes to sustainable shipping through improved fuel economy. Future research could explore experimental validation and broader integration into ship energy management systems.

LIMITS OF THE APPLICATION OF METHODS FOR DETERMINING THE CHANGE IN THE DRAFT OF A SEA VESSEL DUE TO A CHANGE IN THE DENSITY OF WATER

A. M. Andreev, T. A. Stovba — Wed, 23 Jul 2025 00:00:00 +0300

Abstract The article considers the problem of determining the change in the draft of a seagoing vessel due to a change in water density. Its practical significance is closely related to solving the problems of safe navigation. One such problem is the calculation of a vessel's draft at the stage of developing its cargo plan. Another is determining the cargo mass based on measuring the vessel's draft before and after cargo operations. A comparative analysis of several methods for determining the change in a ship's draft due to a change in water density has revealed the limits of their practical application. These limits are defined by the assumptions made when deriving the working formula. Failure to consider these limits can lead to gross errors in draft calculations and, in practice, to incorrect vessel loading. The methods under consideration are illustrated with specific examples.

The article also demonstrates the potential for expanding the practical significance of the marginal estimation method for determining draft changes not only in straight-walled vessels. The method is also useful in cases such as: estimating the upper limit of draft change caused by a change in water density; determining draft changes in cases where water density does not vary significantly during the ship’s passage.

A criterion is proposed that allows for evaluating the accuracy of the marginal estimation method for determining draft changes. In particular, it is shown that it is possible to identify critical values of the vertical fineness coefficient for a certain draft range at which the error of the marginal estimation method equals a specified value (for a given difference in water density). This criterion allows us to assess the conditions under which the discrepancy between the results of "exact" methods and the marginal estimation method may be acceptable for practical purposes.

Important areas of further research are related to improving the accuracy of measuring the ship’s draft and the water density, as the errors in these measurements significantly limit the accuracy of determining the vessel's displacement.

INTEGRATION OF RISK ANALYSIS IN THE ASSESSMENT OF ENERGY EFFICIENCY OF SHIPS AT CHANGING SPEED REGIMES

M. Bulgakov, O. Melnyk, A. Aleksishyn, O. Mazur, O. Onishchenko — Wed, 23 Jul 2025 00:00:00 +0300

The article presents a comprehensive mathematical model for risk assessment in slow steaming conditions, integrating energy efficiency, greenhouse gas emissions and operating costs. Simulations for different types of ships in several speed scenarios were carried out, which allowed the determination of the relationship between fuel economy and the accumulation of relevant risks associated with the human factor, technical malfunctions and adverse weather conditions. An integral performance indicator that considers both environmental benefits and potential costs of eliminating the consequences of accidents is proposed. The simulation results have revealed the existence of an optimal speed range for each type of ship, at which the best compromise between energy and environmental efficiency and operational safety is achieved. Dynamic risk modeling has shown that long voyages without the adaptation of control and prevention systems lead to a rapid increase in the cost of eliminating the consequences. The results obtained are of practical value for shipping companies to develop adaptive strategies for managing the speed of vessels that combine environmental goals with ensuring the safety and financial sustainability of maritime transportation.

FORMATION OF THE SHIP'S OBSERVATION ACCURACY FIELD USING MULTIPLE LANDMARKS

D. S. Zhukov, B. M. Alieksieichuk — Wed, 23 Jul 2025 00:00:00 +0300

Abstract. This paper highlights the fact that the presence of navigational obstacles, such as shoals, significantly increases the risk of maritime accidents when vessels operate in confined or restricted waters. Such obstacles create unpredictable conditions where the margin for navigational error is minimal. Errors in navigational measurements, as well as inaccuracies in ship maneuvering, contribute to heightened risks of grounding, collision, and close-quarter situations. In areas with high traffic density, the danger is further amplified, increasing the likelihood of navigational conflicts and incidents.

A particularly critical factor affecting navigational safety, especially in zones with unreliable reception of satellite navigation signals, is the accuracy of determining a vessel’s position using traditional navigation landmarks. In such cases, reliance on visual or radar-based observation becomes essential. Therefore, it is important to assess how accurately the position of a ship can be determined when using multiple fixed landmarks.

To develop an observation accuracy field for a vessel, based on several landmarks, a scalar accuracy measure is applied to each point within the coastal navigation area. The most appropriate measure for this purpose is the dispersion of the modulus of the vector error. This measure provides a quantitative indicator of how precisely the vessel’s location can be determined based on the geometry and accuracy of the observations.

An analytical expression for the accuracy index is presented for cases involving distance and bearing measurements to each landmark, assuming normally distributed errors along position lines. To visualize the field of observation accuracy across a navigational area, a computer simulation model was created.

The scalar accuracy index was calculated for scenarios involving two, three, and four landmarks. The index value influences the degree of shading applied to each grid section in the accuracy field, darker shading corresponds to higher accuracy indices. The resulting accuracy field can be digitized and displayed on an electronic chart, offering mariners a visual representation of positional confidence throughout the area.

OPTIMIZATION OF THE OPERATION OF MARINE DIESEL ENGINES USING WIRELESS MONITORING SYSTEMS

V. V. Nikolskyi, M. V. Slobodyanyuk, M. V. Levinskyi, M. V. Nikolskyi — Wed, 23 Jul 2025 00:00:00 +0300

The subject of this research involves the development and integration of wireless monitoring systems designed to enhance the operational efficiency and reliability of ship diesel engines, with a particular focus on emergency diesel generators such as the Kohler 50EOZD. The aim of the study is to assess the feasibility, advantages, and limitations of implementing wireless technologies for real-time diagnostics and predictive maintenance in the context of shipboard power systems.

The methodology is based on a comparative analysis of traditional wired monitoring systems and modern wireless sensor networks (WSNs), as well as the modeling of engine operating parameters and failure modes using simulation tools. The study also includes an empirical component based on the technical and operational characteristics of the Kohler 50EOZD generator. Particular attention is given to the challenges of ensuring signal integrity, data transmission reliability, and cyber-physical security in the harsh marine environment.

This research is relevant due to the growing complexity of naval power systems, the demand for autonomous operation, and the global trend toward digitization of maintenance processes. The scientific novelty lies in the proposed approach to integrating adaptive wireless systems for early fault detection, which can significantly reduce downtime and maintenance costs.

The main results confirm that the use of wireless diagnostic systems allows for real-time condition monitoring of critical engine parameters, improving fault detection accuracy and enabling data-driven maintenance strategies. The practical significance of the study is the potential to apply these solutions in both military and commercial maritime engineering sectors.

The conclusions emphasize the viability of wireless monitoring as a scalable and efficient tool for optimizing the performance and serviceability of shipboard diesel engines.

MODELS FOR SIMULATING RADAR ECHO SIGNALS IN A VIRTUAL TRAINING SYSTEM

A. Petrovskyi — Wed, 23 Jul 2025 00:00:00 +0300

In the current context of educational process transformation, ensuring the effective acquisition of practical skills by cadets in maritime academies has become increasingly important. Restrictions related to physical attendance in classrooms, along with the high cost of commercial cloud-based simulators, significantly limit the possibilities for interactive training of navigators. Simulator systems based on hardware-software integration are often difficult to scale in line with modern educational demands. Against this background, the development of mathematical models enabling real-time radar echo simulation without dependence on physical hardware is a promising direction of research. This article presents mathematical models designed to graphically simulate radar echo reflections from moving and stationary surface objects. A method of dynamic angular shadow intervals is proposed. The construction of sinusoidal radar echoes along “visible” segments (2D facets) of a polyline (Land Danger contour) enables realistic visualization of radar signals while considering the geometry of surface targets. These sinusoidal profiles are then combined into a unified radar response within the polar radius. The article introduces a model of a unique visibility metric for 2D facets in a polar sector, calculated analytically rather than constructed via bit masking. The logic of dynamic “shadow accumulation”—expanding angular shadow intervals over time—represents a novel implementation of the “dynamic occlusion” concept in a polar observation space relative to a moving vessel. The provided echo signal simulation model corresponds to the real one without taking into account the physical shadow zones of the ship's radar, which are formed due to the arrangement of high deck structures on the vessel that obstruct the circular propagation of the radar signal.

FUNCTIONAL DIAGNOSTICS OF SHIPBOARD HIGH-VOLTAGE ELECTRICAL MACHINES

K. V. Tymofeiev, S. V. Voronenko, Y. O. Lebedenko — Wed, 23 Jul 2025 00:00:00 +0300

The article is devoted to the development of methods for the functional diagnostics of high-voltage electrical machines and their practical application in maritime transport. An analysis of the main approaches to the development of diagnostic techniques and tools for electrical machines demonstrates the feasibility of using integrated functional diagnostics. The set of diagnostic parameters must meet the requirements of completeness of description of all classes of defects, maximum sensitivity to changes in the values of structural parameters, minimum composition, accessibility for control and measurement, minimum cost and time of control and measurement, sufficient resolution in recognizing individual defects. The analysis of diagnostic parameters made it possible to form an effective set that includes parameters of vibration, temperature, current consumption and capacitance, and electro-discharge activity. The most effective application of these methods is the joint use of an integrated diagnostic system.

An algorithm for the complex functional diagnostics of shipboard high-voltage electrical machines has been developed. The structure for the system for diagnosing the technical condition is proposed, which allows to implement the developed diagnostic algorithm and is characterized by constructive simplicity and reliability. The complex diagnostics of high-voltage electrical machines can be formalized by means of models of classification of the technical condition and fault finding based on the results of classification. A fuzzy model for classifying the technical condition in the form of predicate rules has been developed, which allows determining the technical condition of an object based on the results of measuring the parameters of electrical discharge activity and the rms value of vibration velocity. Five classes of technical condition of the object are defined: “Normal”, “Normal with deviations”, “Normal with significant deviations”, ‘Deterioration’ or “Pre-emergency”. A fault detection model was developed and implemented using fuzzy logic.

The model makes it possible to detect faults in an object based on the measured values of current and vibration amplitudes at characteristic frequencies, as well as temperatures at control points. A method using a fuzzy model is proposed that searches for faults by the relative deviations of current and vibration amplitudes at characteristic frequencies, as well as temperatures at control points. The algorithm for assessing the technical condition allows to determine the current technical condition of the facility using a fuzzy logic apparatus based on the results of measuring the parameters of electrical discharge activity and the root mean square value of vibration velocity. In the case of a pre-emergency condition, a signal is generated to shut down the electrical machine. The algorithm for fault detection of shipboard high-voltage electrical machines is applied on a fuzzy logic model. The algorithm determines the causes of electrical machine failure based on the results of thermal imaging and spectral analysis of the supply current and vibration.

NEW COMPOSITE MATERIALS MADE PRODUCTS DEVELOPMENT AND IMPLEMENTATION FEATURES

V. O. Protsenko, O. A. Kasyan — Wed, 23 Jul 2025 00:00:00 +0300

The article deals with the techno-economic feasibility of using products made from new composite materials. The proposed cost structure of composite products includes the cost of materials, fillers, reinforcement, processing with stationary or variable physical fields, and mechanical processing by cutting, pressure, or other methods. The costs of performing each operation to manufacture a composite product are proposed to be calculated using a comprehensive approach. These include workers’ wages, electricity expenses, equipment depreciation, costs of operating cutting tools and equipment, machine programming, and other shop costs—in particular, payment for the operation of production areas, ventilation, heating, etc. Ratios are introduced that can be used in practice to determine the specified components of the cost of a composite product. For illustration, calculations and comparisons of the manufacture of deadwood-bearing bushings from graphite-filled caprolon, caprolon filled with graphite and molybdenum disulfide, as well as from an epoxy composite filled with graphite and polyamide, are presented. The expressions for calculating the labor intensity and cost of manufacturing bushings from these materials, depending on their sizes and the relationships between them, were obtained. The calculation results showed that the cost of bushings made from all three analyzed materials are comparable in magnitude—values of the same order—making the manufacturing costs for all options equivalent under unit production conditions at a ship repair enterprise. By determining wear, it is shown that in the case of using bushings from caprolon filled with graphite and molybdenum disulfide, the number of repairs with docking of the vessel during its service life will be almost six times less than when using bushings made from epoxy composite (9 and 23 dockings over 25 years, respectively). The set of results obtained is key for choosing a material, as the greater wear resistance of the bushings reduces the number of vessel downtimes in the dock and the cost of transporting a ton of cargo. The presented calculation method can be used by engineers when justifying the choice of material and is helpful for graduate students to compare the results obtained with studies by other authors. This could be one step toward adhering to the principles of open science and reducing the amount of research conducted merely for the sake of research.

DECISION SUPPORT SYSTEM FOR SELECTING A VESSEL MANEUVER ACCORDING TO THE REQUIREMENTS OF THE COLREG-72

A. P. Ben, V. M. Mateichuk — Wed, 23 Jul 2025 00:00:00 +0300

The article is devoted to the issues of application of the Convention on the International Regulations for Preventing Collisions at sea, 1972 (COLREG-72) in decision support systems (DSS) of the ship navigator. The analysis of research in the field of creation of formal models of COLREG-72 and their practical application in vessel traffic control systems is carried out. It was revealed that at the current time a promising direction of scientific research is the creation of methods for assessing the level of danger of navigational situations in accordance with the requirements of COLREG-72, adapted for use in DSS of the ship navigator. It has been proven that an important aspect of the successful application of COLREG-72 in navigation is not only the creation of their adequate formal models adapted to the use of the ship's DSS and automated vessel traffic control systems, but also the development of training systems for training marine specialists in order to increase their competence in the field of practical skills in applying rules while keeping watch on the navigation bridge. A classification of navigation situations that arise in the process of vessels diverging in accordance with the requirements of COLREG-72 and a method for assessing the level of their danger in accordance with the parameters of vessel movement have been developed. The proposed classification and method for assessing the level of danger of navigation situations have been implemented in the ship navigator's DSS, which is integrated with the navigation equipment of the Wartsila "Navi-Trainer Professional 5000" simulator. Software tools have been created to implement information exchange between the DSS and the simulator's navigation equipment in real time, which allows for constant monitoring of the process of changing navigation situations. The priority area of practical application of the created DSS is to provide simulator training for marine specialists in order to obtain practical skills in using COLREG-72 on the ship's navigation bridge. A promising area of further research is the development of a separate DSS software module for conducting statistical analysis of the success of simulator training of specialists who undergo it on a navigation simulator, in terms of determining the difficulties of applying individual rules of COLREG-72 for different types of navigation situations and sailing conditions.

MODERN METHODS OF PREVENTING SHIP COLLISIONS AND THEIR APPLICATION IN CONTROLLING AUTONOMOUS SHIPS

A. P. Ben, L. O. Pelykhivskyi, O. S. Solovey — Wed, 23 Jul 2025 00:00:00 +0300

The article is devoted to the issues of applying methods for preventing ship collisions in the processes of controlling unmanned autonomous vessels (UAVs). A range of important issues of the current state of development of the autonomous and unmanned vessel industry is outlined. A comparative analysis of existing methods for preventing ship collisions is conducted. The disadvantages and advantages of each method are identified, as well as the features of their practical application in UAV control. The structure and distinctive features of the process of controlling the movement of autonomous and unmanned vessels in comparison with vessels controlled by a navigator are presented. The peculiarities of the UAV control process are clarified and a range of methods that should be applied for its implementation is determined. The UAV control methods are considered and the architecture of the control system is proposed, which is based on the combined use of fuzzy logic methods, predictive control and explained artificial intelligence. It has been proven that the combination of various methods of processing navigation information and decision-making allows for high-quality control of UAV movement in real time, in the presence of errors and incompleteness of navigation data. Ways of practical implementation of the proposed architecture of the UAV control system and promising directions of further scientific research in this direction are identified.

DETERMINING THE IMPACT OF THE HUMAN OPERATOR FACTOR USING A NAVIGATION SIMULATOR

P. Kochubei, P. Nosov — Wed, 23 Jul 2025 00:00:00 +0300

As maritime operations become increasingly complex, there is a growing need for objective, scalable methods to evaluate seafarer competence beyond traditional instructor-based assessments. This study presents a comprehensive, data-driven framework for analyzing cadet performance in maritime simulator exercises, utilizing state-of-the-art unsupervised learning and explainable AI. The research draws on multivariate time-series data from navigational simulations, capturing vessel dynamics, control actions, and environmental parameters across dozens of features. A rigorous preprocessing pipeline was applied, combining statistical feature aggregation and redundancy reduction through Pearson correlation and Mutual Information. This yielded a compact, yet informative feature set encompassing control inputs, navigational states, and vessel motions. To offset limited number of sessions small in the dataset, each simulation was split into meaningful intervals by applying rolling window statistics. Each window was then encoded as a summary vector, reflecting both central tendencies and temporal variability. The analysis employed the HDBSCAN clustering algorithm, which excels in detecting groups of variable density and naturally identifies outlier behaviors—critical in the context of training evaluation. The resulting clusters were projected into lower-dimensional space via t-SNE, providing interpretable visualizations of cadet performance patterns. To further elicit the distinguishing characteristics of each group, a linear Support Vector Machine was trained to predict cluster membership, with SHapley Additive exPlanations (SHAP) attributing each decision to underlying features. Key findings reveal that clusters align with distinct navigational strategies: stable, conservative approaches are differentiated from more dynamic or risk-prone styles by features such as roll velocity, yaw rate, and engine RPM. Sessions flagged as outliers typically exhibited abrupt maneuvers or inconsistent control usage, highlighting potential skill gaps. The SHAP-based interpretability layer transforms complex model outputs into actionable instructional feedback, enabling targeted interventions and tailored training. Overall, this automated approach has potential to become a transparent, scalable alternative to subjective grading in maritime education, with significant implications for enhancing safety and developing individualized learning pathways. The proposed system demonstrates strong potential for integration into real-world training environments and continuous improvement as more operational data becomes available.

MULTI-CRITERION OPTIMIZATION OF SITUATIONAL MANAGEMENT OF MARITIME TRANSPORTATION UNDER CONDITIONS OF UNCERTAINTY

O. Sharko, D. Stepanchikov, A. Sharko, P. Movchan — Wed, 23 Jul 2025 00:00:00 +0300

A methodology for multi-criteria optimization of maritime transport under conditions of uncertainty in the external environment is proposed. It is noted that in the practice of maritime transport management, complex manifestations of uncertainty are observed in the form of various specific situations, obscured by possible interactions and uncertainties of the external environment. It is shown that the most rational way to solve transport problems under conditions of uncertainty is multi-criteria optimization. Based on the consideration of real situations along the Turkey-Germany transport corridor, it is shown that reducing uncertainty in determining the conditions for navigating transport routes can be achieved both through the rational use of the vessel's operational parameters and by taking into account the external conditions of the route. The parameters for optimizing transport for a specific transport route are proposed and studied in detail. A transport matrix is formed, whose optimization parameters include vessel loading, delivery duration, transit speed, load on the main engine, fuel consumption, route deviation, and transportation cost. Practical cases of route passage are considered. The influence of external disturbances on the vessel’s controlled operational parameters is established, which has allowed the development of recommendations for decision-making based on the ranking of priorities among the optimization parameters of transport matrix strategies, the convergence of various generalizing functions, and the possibility of predicting the consequences of decision-making on the selected optimal management strategy under specific conditions. The diversity of various manifestations of the external environment’s influence on the functioning of transport facilities, global changes in the supply structure, evolving environmental requirements for waste disposal, and other causative factors that are not subject to strict regulation significantly complicate the information support necessary for decision-making under conditions of uncertainty. The adaptation of existing sea transportation technologies to changing operational conditions, driven by fluctuations in the external environment, constitutes the essence and direction of ongoing transformational changes aimed at modernizing the industry.

MODEL AND METHOD FOR CALCULATING MATRICES OF CORRESPONDENCES TAKING INTO ACCOUNT TIME LIMITS OF TRAVEL BENEFITS

V. P. Slavych — Wed, 23 Jul 2025 00:00:00 +0300

The article proposes an improved model for calculating matrices of passenger correspondences, which takes into account time limits of travel benefits. The relevance of the study is due to the need to adapt transport planning to social changes and reduce passenger traffic in conditions of limited funding. Traditional approaches do not take into account the impact of changes in the time of benefits, which leads to distortion of modeling results and inefficient use of resources. The proposed model takes into account the temporal availability of benefits and allows calculating the attraction coefficients between transport areas, taking into account the periods of paid and free travel. Special attention is paid to the analysis of the dynamics of trips of persons of preferential categories at different times of the day, which allows correctly considering peak and interpeak loads. The introduced parameters allow calculating the share of time allocated to each type of travel and combining the corresponding attraction coefficients. Thus, the model reflects the change in the mobility of preferential categories of passengers depending on the time of day, which is especially important for cities with a high share of such passengers. The developed approach also allows assessing potential changes in passenger flows when adjusting the time limits of the benefits, which can be useful for transport management bodies. The paper considers various options for the mutual arrangement of the time intervals of the benefits and the calculation of the corresponding weighting coefficients. The results obtained allow the formation of more accurate and flexible correspondence matrices that take into account social policy in the field of transportation, demand reduction and uneven load on the transport network. The proposed approach is universal in nature and can be adapted to different conditions of public transport operation, contributing to more effective planning of routes and schedules. In addition, the model can be integrated into existing transport modeling information systems for automated consideration of preferential factors.

BEHAVIOR MODELING AND EMERGENCY SIMULATION FOR A MARITIME AUTONOMOUS VESSEL WITH TRAJECTORY STABILITY ASSESSMENT

D. Burlachenko, O. Melnyk — Wed, 23 Jul 2025 00:00:00 +0300

The article investigates the complex behavior of a Maritime Autonomous Surface Ship (MASS) during critical emergency situations. It specifically focuses on scenarios involving loss of control, sudden gusty winds, and steering drive failure. It is demonstrated that studying the emergency behavior of a MASS holds profound practical significance, directly addressing challenges related to the safe deployment and energy efficiency of autonomous navigational transits.

A simplified mathematical model, based on Newton-Euler equations, was employed to characterize the vessel's motion dynamics in the horizontal plane. This model accounts for hydrodynamic, aerodynamic, and stochastic effects in a simplified manner, thereby ensuring a realistic representation of the marine environment.

A critical gap identified in current MASS research is the deficit of models capable not only of reproducing the behavior of autonomous vessels during rudder blockage, loss of control signals, or unexpected disturbances, but also of predicting their cascading consequences. To address this deficiency, an innovative simulation scenario for MASS emergency modes was proposed. This scenario incorporates various navigational element failures. The simulation was conducted in MATLAB/Simulink, enabling the implementation and analysis of key emergency scenarios. This included a discrete integration step of 0.1 seconds over a 100-second simulation period, utilizing typical parameters for a small autonomous platform.

The study evaluated three distinct emergency scenarios:

– in the first scenario, the rudder was fixed at a zero position, leading to irreversible and uncontrolled course deviation due to wind gusts. This was identified as the most critical outcome, as the vessel loses its ability to perform navigational compensation, although the direction of drift remains predictable;

– the second scenario involved simulating a delay in the PID controller's command signal, mimicking an unstable connection. This revealed deviations from the desired course, indicating a partial retention of trajectory. However, it underscored that prolonged delays can induce not only aperiodic effects but also resonance, thereby necessitating adaptive control algorithms;

– in the third scenario, with the PID controller actively engaged, the system demonstrated a robust capability to quickly compensate for a strong lateral wind gust. The vessel's course stabilized within a few seconds after a minor transient overshoot, confirming a partial invariance to disturbances.

The simulation results provided invaluable insights into trajectory stability and the varying effectiveness of control strategies under adverse conditions. The presented approach to simulating critical states, achieved by fixing motion parameters during loss of control, established a fundamental database for developing proactive crisis response protocols. Furthermore, the classic PID control model was enhanced with a "freeze" function for actuators and adapted to account for changes in load and transverse speed. This enables the creation of redundant autonomous control loops, potentially through digital twin technologies. These data serve as a foundation for developing new automatic emergency response algorithms aimed at mitigating unforeseen and critical situations during future autonomous navigation missions.

CREATION OF AN INTEGRATED MODEL FOR ENSURING OPERATIONAL SHIP SAFETY

P. Nykytyuk, O. Melnyk — Wed, 23 Jul 2025 00:00:00 +0300

The article proposes a novel integrated mathematical model meticulously designed to enhance the operational safety of ships. This comprehensive model seamlessly combines several critical components: probabilistic risk assessment, providing quantitative measures of potential hazards; an in-depth analysis of the degradation of safety barriers, tracking the erosion of protective layers over time or under stress; an aggregate evaluation of the real-time state of various ship subsystems, unifying heterogeneous data for a holistic view; and robust risk prediction capabilities grounded in advanced neural network technologies, enabling the forecasting of future risk trajectories based on learned patterns from complex operational data.

Building upon a robust modeling methodology, a series of five distinct operational scenarios were rigorously simulated. These scenarios were carefully crafted to encompass a wide spectrum of ship functioning conditions, critically considering dynamic environmental changes, various technical failures (e.g., machinery malfunctions, system breakdowns), and the potential loss of efficiency in existing security and safety systems. Such comprehensive scenario testing allows for a thorough validation of the model's performance across diverse and challenging operational contexts.

The simulation results unequivocally demonstrate the proposed model's exceptional ability to detect dangerous conditions at remarkably early stages of their development, far before they escalate into critical incidents. Furthermore, the model is capable of generating precise quantitative risk assessments, offering clear numerical insights into potential threats. Crucially, it also produces actionable recommendations for preventive response, empowering decision-makers with timely and relevant guidance to avert adverse events. The embedded indicators for integrated risk, safety margin, and continuous safety barrier degradation monitoring collectively confirm the system's high information content, providing a rich, multi-faceted understanding of the ship's safety status. This also highlights its remarkable adaptability within a highly dynamic maritime environment, where conditions can change rapidly and unpredictably. The innovative approach presented in this work can therefore serve as a foundational basis for the creation of sophisticated functional platforms dedicated to comprehensively managing the safety of marine vessels. Moreover, it offers significant potential for seamless integration into modern navigation and broader information management systems, thereby paving the way for more resilient, predictive, and proactively managed maritime operations in the future.

THEORETICAL MODELS OF APPROXIMATION OF WAVE CORRECTIONS IN UNDER KEEL CLEARANCE CALCULATIONS

A. Petrovskyi, A. Ben — Wed, 23 Jul 2025 00:00:00 +0300

Year after year, maritime transportation continues to grow, with an increasing count of ships and their displacement requiring enhanced navigational skills and precision. Weather factors such as wind and waves significantly influence a vessel's ability to maintain position and accurately determine safe depths, making them critical for safe navigation.

This article aims to derive analytical dependencies for the Swell parameter based on vessel length and wave height within the most common operational ranges for ships. It also provides tabulated Swell values and a software product designed for cadet training alongside the NaviSailor 4000 simulator. The article analyzed existing accounting methods for wave-induced increases in vessel clearance. It was found that no proposed method provides practical recommendations for calculating the Swell parameter for any ship length or wave height. Although tables containing the desired parameter exist, additional interpolation calculations are required to determine the Swell value. To address this, preliminary calculations were performed using interpolation of known values for this parameter. Then, ensuring maximum alignment with reference data, mathematical models were developed for each 10-meter increment in vessel length and each 0.5-meter increment in wave height. Through extrapolation, with constraints on wave amplitude values, specific Swell parameter values were determined by tabulating functions. The resulting table of Swell values allows for direct application without the need for prior interpolation calculations. Based on these models, the WaveCheckRoute software was developed. This tool enables users to work with weather maps in .grib format for any forecast step, overlay routes in .rt3 format, select vessel schedules, and analyze dangerous wave heights along a route at estimated arrival times. The analysis is conducted based on weather forecast intervals and vessel speed, enhancing passage planning and safety in maritime navigation.

SPECIFICS OF MATHEMATICAL AND COMPUTATIONAL MODELING OF CAR AERODYNAMICS WITH A REAR WING

S. A. Rusanov, O. I. Kliuiev, Ya. V. Shyltsin, M. S. Drozdov — Wed, 23 Jul 2025 00:00:00 +0300

This article explores the specifics of mathematical and computational modeling of automotive aerodynamics involving a rear wing. The main focus is on assessing the degree to which the aerodynamic effects of the rear wing and the vehicle body can be considered additive when analyzed separately. Due to the inherent nonlinearity of the Navier–Stokes equations, and even more so with the inclusion of turbulence modeling equations, complete additivity is theoretically unattainable. Nevertheless, this question remains practically important, particularly given that rear wings are often sold as aftermarket aerodynamic components with manufacturer-quoted downforce values derived from simulations or tests performed in isolation from the vehicle.

To investigate this issue, a series of numerical experiments were conducted using CFD techniques that replicate wind tunnel testing conditions. The simulations addressed an external flow problem using the k-ε turbulence model. Three configurations were modeled and compared: the vehicle without the rear wing, the standalone rear wing in free stream, and the complete vehicle with the rear wing installed.

The results show that the downforce generated by the wing when mounted on the vehicle is greater than that produced by the same wing in an isolated flow. Similarly, the aerodynamic drag of the rear wing increases when it is installed on the car. These differences arise due to modifications in the flow field caused by the presence of the vehicle body. Specifically, the airflow velocity approaching the wing is higher when the wing is mounted on the vehicle than under free stream conditions. Additionally, significant vortex structures are formed in the space between the wing and the vehicle body, which contribute to a localized pressure drop behind the wing and in this intermediate region. This intensified vortex activity results in greater aerodynamic forces compared to those observed in the isolated case.

PRACTICAL METHODS FOR CALCULATING THE POSITION OF THE BASIC POINTS OF THE SUBSTANTIVE MODEL OF THE SHIP'S TURN

O. M. Tovstokoryi — Wed, 23 Jul 2025 00:00:00 +0300

The object of the study is the process of turning the ship. It is necessary to numerically calculate the positions of all the base points of the substantive model.

Knowledge of the substantive model of ship turning and methods for calculating the positions of the base points allow us to calculate the process of turning the ship and determine the positions of the base points. The position of the center of gravity is taken from the ship's cargo plan. The position of the pivot point and the position of the center of rotation are determined by simple experimental and experimental-calculation methods.

Determining the position of the center of rotation and the pivot point makes it possible to determine the position of the ship during turning much more accurately, which will increase the safety of navigation.

Determination of the abscissa of the pivot point by the tangential speeds of the bow and stern can be used for a vessel with any type and number of main engines and any type and number of thrusters.

Determination of the displacement of the center of rotation from the center of gravity by comparing the positions of the abscissa of the pole of rotation at zero and maximum vessel speeds, determined by the tangential speeds of the bow and stern, can be used for a vessel in which the lateral force is generated in different ways, but in the same place both at zero speed and at full speed.