Araştırmacılar(3)

• Işilak, C.
• Kılıç, Uğur
• Tatli, Ali

• ArticleYalnız künye2026/r/ebyu/10985
  An adaptive hybrid energy management system for UAVs integrating fuzzy logic, solar forecasting and real-time control

  Can, Erol

  This study presents a hybrid energy management system (EMS) for unmanned aerial vehicles (UAVs), integrating flexible photovoltaic (PV) panels with a high-capacity lithium-polymer (Li-Po) battery to enhance flight endurance and energy resilience. The proposed EMS features a multi-layered adaptive control architecture, combining fuzzy logic-based decision-making, short-term solar irradiance prediction using machine learning and closed-loop proportional-integral-derivative (PID) motor control. This architecture dynamically allocates power based on real-time solar irradiance, battery state of charge (SOC) and propulsion load. The approach aims to minimise battery stress while ensuring stable UAV operation under variable environmental conditions. Simulation results indicate that, without PV support, the UAV battery depletes in approximately 28 min. However, incorporating an 80 W PV panel extends the endurance to 37 min, and a 160 W effective PV configuration increases the flight time to over 50 min, while maintaining the SOC above 20%. This corresponds to a 79% improvement in endurance and nearly a 50% reduction in net battery energy consumption. The EMS effectively mitigates deep discharge cycles, improving battery health and operational lifespan. These findings demonstrate that the proposed hybrid EMS provides a scalable, adaptive and computationally efficient solution for balancing renewable and stored energy. It outperforms conventional static or single-source control strategies, particularly under fluctuating solar conditions.

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• ArticleYalnız künye2026/r/ebyu/10673
  Comparative environmental performance of high-speed rail and air transport on Japan's domestic short-haul routes: A case-based evaluation using EUROCONTROL's IMPACT

  Çam, Ömer; Kılıç, Uğur; Tanrıverdi, Gökhan

  Air transportation offers significant speed advantages, particularly on medium- and long-haul routes, yet it contributes disproportionately to environmental pollution, especially on short-haul domestic flights. In contrast, high-speed rail (HSR) represents a more sustainable alternative. This study examines CO2 emissions from narrow-body and wide-body aircraft in comparison with Shinkansen trains on selected Japanese domestic routes, where air and HSR services directly compete, focusing on the Haneda–Osaka and Haneda–Fukuoka corridors. Japan is notable for having the highest use of wide-body aircraft on domestic routes worldwide, which makes this context particularly relevant for examining the environmental impact of aircraft type. Emission data for each aircraft type were obtained using the integrated aircraft noise and emissions modeling platform (IMPACT) developed by EUROCONTROL. The results indicate that wide-body aircraft emit at least twice as much CO2 as narrow-body jets, highlighting the critical influence of aircraft type on short-haul emissions. Shinkansen trains, particularly the N700 series, demonstrate the lowest per-passenger emissions, achieving approximately 20% greater efficiency than the older 700 series. The study provides policymakers with a meaningful perspective, emphasizing that deploying wide-body aircraft on short-haul routes is inconsistent with environmental sustainability goals.

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• ArticleYalnız künye2026/r/ebyu/10172
  Diode-based programmable network array (DiProNA) for high-impact reconfigurable instrumentation

  Can, Erol

  The increasing complexity and integration density of modern mixed-signal and high-frequency systems demand reconfigurable, precise, and fault-tolerant signal-routing architectures. Conventional switching matrices based on multiplexers or crossbar networks suffer from crosstalk, leakage, limited scalability, and weak fault tolerance, making them unsuitable for emerging precision analog platforms. Addressing these limitations, this work introduces the Diode-Based Programmable Network Array (DiProNA), a novel hybrid switching architecture that differs fundamentally from existing structures by combining MOSFET-based programmability with unidirectional diode-assisted conduction paths to achieve intrinsic fault isolation, current sharing, and enhanced thermal robustness. A comprehensive analytical model—developed using Thevenin equivalents, nodal analysis, and explicit inclusion of diode and MOSFET parasitics—is presented and validated through extensive circuit-level simulations. Clear modeling assumptions (such as quasi-static device behavior and linearized small-signal parasitics) are stated to ensure transparency and reproducibility. Quantitative comparisons with traditional multiplexer and crossbar matrices demonstrate that DiProNA achieves higher voltage accuracy, lower effective resistance, and significantly reduced short-circuit current. Series ballast resistors effectively constrain fault currents and mitigate thermal stress, enabling reliable operation under open-circuit, short-circuit, and partial-failure scenarios. Multi-source configurations further enhance efficiency and distribute power-thermal load, while dynamic evaluations confirm microsecond-level response times with minimal overshoot, supporting high-speed instrumentation front-ends. Collectively, the results position DiProNA as a scalable, efficient, and fault-tolerant routing solution suitable for adaptive data converters, SoC subsystems, wireless front-ends, and biomedical instrumentation. This work establishes DiProNA as a robust and versatile platform advancing next-generation programmable mixed-signal systems.

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• ArticleYayıncıda açık erişim2025/r/ebyu/19430
  Runway configuration analysis based on wind data: a case study of warsaw chopin airport

  Sahin, Ozlem; Tatlı, Ali

  Runway configuration at airports is determined based on the prevailing wind direction to ensure the safety of flight operations. In this process, wind direction, crosswind component, and wind coverage are of critical importance. In this study, Warsaw Chopin Airport, which has intersecting runways, is examined. Using 12 years of METAR data for the airport, wind speed, wind direction, and wind coverage were analyzed. Finally, monthly wind contour models were generated for the airport, and the relationship between wind and runway configuration was evaluated seasonally. Based on the wind data from Warsaw Chopin Airport, it was found that the prevailing wind directions are west, northwest, and east-southeast; the average wind direction is 250°, while the maximum and minimum wind directions are 270° and 360°, respectively. Additionally, the wind coverage was calculated as 99.77% with the combined use of the existing intersecting runways, indicating that the current runway configurations are operationally highly sufficient.

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• ArticleYalnız künye2025/r/ebyu/12205
  A multi-sensor approach for precision UAV landing on dynamic platforms under challenging conditions

  Işilak, C.; Oktal, H.

  This study presents the design and evaluation of an autonomous landing system for rotary-wing unmanned aerial vehicles (UAVs) targeting moving platforms. The proposed system leverages the UAV's onboard positional data and the moving platform's position, velocity and orientation information to execute high-precision landings. By incorporating the GPS coordinates provided by the mobile platform, the operational envelope of the landing procedure is significantly extended. A Kalman filter is employed to fuse the platform's GPS data with the UAV's inertial orientation measurements, enabling accurate estimation of a dynamic rendezvous point along the platform's trajectory. This facilitates the generation of an optimised landing trajectory that minimises path length and enhances energy efficiency. A YOLOv8-based object detection model is integrated into the system to detect the landing pad in real time. The effectiveness of the proposed method is validated through scenario-based simulations designed to evaluate landing performance under variable altitudes, crosswind disturbances and limited visibility due to fog. Across 30 independent runs, the proposed method reduced total autonomous landing time by 12% (191 ± 2.0 s → 168 ± 1.6 s, p < 0.001), halved the landing phase (22.9 ± 0.7 s → 11.1 ± 0.7 s), shortened the path by =152 m (2035 ± 6.8 m → 1883 ± 3.1 m), and lowered battery consumption from 5.0 ± 0.1% to 4.0 ± 0.1%. The system maintained successful landings under variable wind (up to 6 m/s) and fog with a 7 m detection range, achieving sub-meter touchdown accuracy (RMSE =0.15 m); at a 5 m detection limit, landings failed, indicating a robustness boundary. Compared to existing literature, the developed system introduces a novel 3D trajectory planning approach involving altitude variations and dynamic target prediction. The framework is modular and compatible with various UAV and ground vehicle platforms, making it suitable for diverse mission profiles in both civilian and defense applications.

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• ArticleYayıncıda açık erişim2025/r/ebyu/11895
  Short-term multivariate airworthiness forecasting based on decomposition and deep prediction models

  Tatli, Ali; Filik, Tansu; Bocu, Erdogan; Karakoc, Hikmet Tahir

  This study introduces a model for predicting airworthiness in terms of meteorology information within the viewpoint of not only formal regulations but also informal rules based on acquired indicators from flight training organization experience (AIs-FTOE). The case study is carried out in the Hasan Polatkan Airport which is used by the Department of Flight Training of Eskişehir Technical University (ESTU-P), which is also recognized as a flight training organization. Within the study, the constraints (derived from regulations and AIs-FTOE) and the data set used in models are explained. Also, the models are introduced based on the gated recurrent unit (GRU) and long short-term memory (LSTM) with the use of empirical mode decomposition (EMD) and variational mode decomposition (VMD). Finally, a model-selective mechanism (MSM) is proposed to use the models in common. The findings show that the models presented in the study produce successful results that can be used in flight training organization's (FTO) planning studies. The MSM uses GRU and LSTM together with decomposition techniques to provide more advanced prediction capabilities. When the literature is examined, it is observed that although meteorological conditions are of vital importance in the efficiency of FTOs, there are not enough studies on airworthiness based on meteorology. So, a model that will assist in scheduling plans is presented for FTOs. Airworthiness analysis of forecasting can provide a comprehensive reference to support planning efficiency in FTOs. To the authors' knowledge, this study will be the first in the literature on airworthiness that presents the MSM using a hybrid deep learning algorithm and decomposition of time series models in concurrent.

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• ArticleYayıncıda açık erişim2025/r/ebyu/10965
  Fully Insulated Dual Output DC-DC Converter Battery Charging System with Single Dynamo Input at the Electric Vehicle

  Can, Erol; Kürşat Demirci, Oğuz

  Battery charging and regulation for the electrical system of electric cars or fuel cars are of great importance for the efficient operation and comfort of the vehicles. In this study, a DC-DC boost converter system that can charge two batteries isolated from each other with the same dynamo for a car is presented. With this system, it is possible to charge two different batteries at their nominal voltages at the same time by increasing the voltage of the system at the low voltage inputs that will occur. First, the circuit model and mathematical expansions that give the operating logic of the circuit are given. Then, the designed circuit model is operated between the modulation indexes of 0.2-0.5 and two different batteries are fed at their nominal voltages in isolation from each other. After the simulation studies, the current and voltage values of the circuit elements and the charging parameters of the battery are measured and the system application is carried out. According to the obtained results, although the charging circuit receives low voltage from the alternator, the two batteries can be charged to the requested level with the proposed system.

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• ArticleYayıncıda açık erişim2024/r/ebyu/12831
  PID Control of Hybrid DC-DC Converter System in Complex Load with Double Reference Time

  Can, Erol; Gülnahar, Murat

  DC-DC converters are circuits that are widely used in energy distribution systems, in industry and technology applications, as well as in household appliances such as computers and televisions, and in uninterruptible power supplies used to feed all these systems. For the design and optimization of DC-DC converter circuits, it is important to create and analyze mathematical models according to the load it is connected to. Simple load structures and circuit structures have been examined and control units have been designed in studies carried out to date. In this study, while the DC-DC converter with a more complex load structure is discussed, mathematical analysis and PID control of DC-DC converters with Buck-Boost feature are performed with the same modulation index in different time periods. In the results obtained, it is shown how to create the mathematical models of a system that provides DC-DC energy conversion with a complex load structure and how to formulate the PID control in a system with this complex load structure.

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• ArticleYalnız künye2024/r/ebyu/12790
  Torques and the speed vibrations reducing and optimization of asynchronous motor with ECCA-PID controlling in power system

  CAN, EROL

  In renewable energy-sourced power systems, asynchronous motors serve as elements that both produce and consume electricity. The stability and efficiency of the asynchronous motor in renewable energy system should be considered. Although performance optimization studies have been carried out using power circuits that control the asynchronous motor fed with solar energy and control units such as proportional, integral, derivation (PID), and Fuzzy logic; They may be insufficient to eliminate and reduce vibrations in the output values of an induction motor fed with a renewable energy source. Losses occur as the system performance decreases constantly due to oscillations. In this study, an induction motor power system is optimized with the extra control coefficient (ECCA)-PID, which provides semi-linear control for the first time, unlike the power systems controlled by other linear controllers used so far to reduce oscillations, and the vibration losses are eliminated. The speed oscillations, torque oscillations, and oscillation losses of the induction motor in the system are controlled by conventional PID, and Fuzzy logic controllers in order to demonstrate the effectiveness of the proposed method in simulation and experimentation. Then, the results are compared after the proposed method are examined. As a result of the comparisons, while the motor oscillations and losses in the power system continue throughout the control period in traditional control methods, the proposed method reduces the losses to zero in a large part of the control period.

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• ArticleYalnız künye2024/r/ebyu/12689
  A new high-frequency multilevel inverter effecting cables weight and energy efficiency of aircraft

  Can, Erol; Kilic, Ugur

  Purpose: Static inverters are very important for the emergency energy distribution system of aircraft and similar machines. At the same time, the electrical energy produced at high frequency for electrical devices is used to reduce the weight of the cables in the aircraft and spacecraft because of the skin effect. In the high-frequency system, a thinner cable cross-section is used, and a great weight reduction occurs in the aircraft. So, fuel economy, less and late wear of the materials (landing gear, etc.) can be obtained with decreasing weight. This paper aims to present the development of a functional multilevel inverter (FMLI) with fractional sinus pulse width modulation (FSPWM) and a reduced number of switches to provide high-frequency and quality electrical energy conversion. Design/methodology/approach: After the production of FSPWM for FMLI with a reduced component, which, to the best of the authors’ knowledge, is presented for the first time in this study, is explained step by step, and eight operating states are given according to different FSPWMs operating the circuit. The designed inverter and modulation technique are compared by testing the conventional modular multilevel inverter on different loads. Findings: According to application results, it is seen that there is a 50% reduction in cross-section from 100 Hz to 400 Hz with the skin effect. At 1000 Hz, there is a 90% cross-section reduction. The decrease can be in cable weights that may occur in aircraft from 10 kg to 100 kg according to different frequencies. It causes less harmonic distortion than conventional converters. This supports the safer operation of the system. Compared to the traditional system, the proposed system provides more amplitude in converting the source to alternating voltage and increases the efficiency. Practical implications: FSPWM is developed for multilevel inverters with reduced components at the high frequency and cascaded switching studies in the power electronics of aircraft. Social implications: Although the proposed system has less current and power loss as mentioned in the previous sections, it contains fewer power elements than conventional inverters that are equivalent for different hardware levels. This not only reduces the cost of the system but also provides ease of maintenance. To reduce the cable load in aircraft and create more efficient working conditions, 400 Hz alternative voltage is used. The proposed system causes less losses and lower harmonic distortions than traditional systems. This will reduce possible malfunctions and contribute to aircraft reliability for passengers and cargo. As technology develops, it is revealed that the proposed inverter system will be more efficient than traditional inverters when devices operating at frequencies higher than 400 Hz are used. With the proposed inverter, safer operation will be ensured, while there will be less energy loss, less fuel consumption and less carbon emissions to the environment. Originality/value: The proposed inverter structure shows that it can provide energy transmission for electrical devices in space and aircraft by using the skin effect. It also contains less power elements than the traditional inverters, which are equivalent for different levels of hardware.

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