Daniel Rohacs

Dr. Daniel Rohacs

Department of Aeronautics, naval Architecture and railway vehicles, Budapest University of Technology and Economics, Budapest, Hungary

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Dinh-Dung NguyenDinh-Dung Nguyen
Dinh-Dung Nguyen
JRJozsef Rohacs
Jozsef Rohacs
Daniel RohacsDaniel Rohacs
Daniel Rohacs
With the exponential growth of numerous drone operations ranging from infrastructure monitoring to even package delivery services, the integration of UAS in the smart city transportation systems is an actual task that requires radically new, sustainable (safe, secure, with minimum environmental impact and life cycle cost) solutions. The primary objective of this proposed option is the definition of routes as desired and commanded trajectories and their autonomous execution. The airspace structure and fixed routes are given in the global GPS reference system with supporting GIS mapping. The concept application requires a series of further studies and solutions as drone trajectory (or corridor) following by an autonomous trajectory tracking control system, coupled with autonomous conflict detection, resolution, safe drone following, and formation flight options. The second part of the paper introduces such possible models and shows some results of their verification tests. Drones will be connected with the agency, designed trajectories to support them with factual information on trajectories and corridors. While the agency will use trajectory elements to design fixed or desired trajectories, drones may use the conventional GPS, infrared, acoustic, and visual sensors for positioning and advanced navigation. The accuracy can be improved by unique markers integrated into the infrastructure.

14 December 2020 in Applied Sciences
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Dinh-Dung NguyenDinh-Dung Nguyen
Dinh-Dung Nguyen
JRJozsef Rohacs
Jozsef Rohacs
Daniel RohacsDaniel Rohacs
Daniel Rohacs
Anita BorosAnita Boros
Anita Boros
Smart mobility and transportation, in general, are significant elements of smart cities, which account for more than 25% of the total energy consumption related to smart cities. Smart transportation has seven essential sections: leisure, private, public, business, freight, product distribution, and special transport. From the management point of view, transportation can be classified as passive or non-cooperating, semi-active or simple cooperating, active or cooperating, contract-based, and priority transportation. This approach can be applied to public transport and even to passengers of public transport. The transportation system can be widely observed, analyzed, and managed using an extensive distribution network of sensors and actuators integrated into an Internet of Things (IoT) system. The paper briefly discusses the benefits that the IoT can offer for smart city transportation management. It deals with the use of a hierarchical approach to total transportation management, namely, defines the concept, methodology, and required sub-model developments, which describes the total system optimization problems; gives the possible system and methodology of the total transportation management; and demonstrates the required sub-model developments by examples of car-following models, formation motion, obstacle avoidances, and the total management system implementation. It also introduces a preliminary evaluation of the proposed concept relative to the existing systems.

28 April 2020 in Sustainability
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AWAgnes Wanjiku Wangai
Agnes Wanjiku Wangai
Daniel RohacsDaniel Rohacs
Daniel Rohacs
Anita BorosAnita Boros
Anita Boros
Generally, the development process of the railway transport system is determined by the market pull effects initiated by the economy and society and the market push effects induced by technological progress. The policymakers can provide a balance between these two effects; this results in more effective, safer, and greener future railway systems. In developing countries, the railway systems lag compared to the developed economies. Therefore, the supporting management tools and legal supports for policymakers and strategic management play significant roles in the development of future sustainable transport systems. This paper deals with such required tools and the potential legal framework that support the development of sustainable railway systems in developing countries. The major novelty and advantages of the introduced methodology is the harmonised interaction between society, economic demands, technological development, and regulation. The proposed tools are applied to the Kenya rail system development.

19 August 2020 in Sensors
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UKUtku Kale
Utku Kale
JRJozsef Rohacs
Jozsef Rohacs
Daniel RohacsDaniel Rohacs
Daniel Rohacs
Due to the introduction of highly automated vehicles and systems, the tasks of operators (drivers, pilots, air traffic controllers, production process managers) are in transition from “active control” to “passive monitoring” and “supervising”. As a result of this transition, the roles of task load and workload are decreasing while the role of the mental load is increasing, thereby the new type of loads might be defined as information load and communication load. This paper deals with operators’ load monitoring and management in highly automated systems. This research (i) introduces the changes in the role of operators and requirements in load management, (ii) defines the operators’ models, (iii) describes the possible application of sensors and their integration into the working environment of operators, and (iv) develops the load observation and management concept. There are some examples of analyses of measurements and the concept of validation is discussed. This paper mainly deals with operators, particularly pilots and air traffic controllers (ATCOs).

13 May 2021 in Sustainability
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UKUtku Kale
Utku Kale
IJIstván Jankovics
István Jankovics
ANAndras Nagy
Andras Nagy
Daniel RohacsDaniel Rohacs
Daniel Rohacs
The International Civil Aviation Organization is estimated that the number of domestic and international passengers will be expected to reach six billion by 2030. This exponential growth in air transport has resulted in a wide range of adverse effects such as environmental impacts. The purpose of this research is to develop new air traffic management, and operator (pilots, air traffic controllers) load measuring systems in order to save fuel, and flight time, thereby reducing environmental impact, carbon emission, greenhouse gas generation, noise pollution, and operating cost. This paper deals with: (i) dynamic sectorization and airspace configuration (ii) introduction of the highly dynamic approach and landing procedures, (iii) dilemmas of human in sustainability (related to the individuals, the society, the non-governmental organizations, and the managers), and (iv) development of dedicated non-intrusive operator supporting systems based on eye-tracking, heart rate, and electrodermal activity. Due to the consequent effects of these developments, the dynamic sectorization and air space configuration may eliminate the task overload and reduce the actual operator load by 30–40%. With the developed concept of dynamic approach and landing procedures, aircraft will be able to follow better trajectories to avoid residential areas around airports to (i) reduce ground noise, and emission, (ii) avoid encounters severe weather and prevent incidents and accidents, and (iii) decrease landing distance up to 56% in compared to the “published transition route”.

17 May 2021 in Sustainability
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MYMelih YILDIZ
Melih YILDIZ
BBBurcu Bilgiç
Burcu Bilgiç
UKUtku Kale
Utku Kale
Daniel RohacsDaniel Rohacs
Daniel Rohacs
Autonomous Vehicles (AVs) represent an emerging and disruptive technology that provides a great opportunity for future transport not only to have a positive social and environmental impact but also traffic safety. AV use in daily life has been extensively studied in the literature in various dimensions, however; it is time for AVs to go further which is another technological aspect of communication. Vehicle-to-Vehicle (V2V) technology is an emerging issue that is expected to be a mutual part of AVs and transportation safety in the near future. V2V is widely discussed by its deployment possibilities not only by means of communication, even to be used as an energy transfer medium. ZalaZONE Proving Ground is a 265-hectare high-tech test track for conventional, electric as well as connected, assisted, and automated vehicles. This paper investigates the use of drones for tracking the cars on the test track. The drones are planned to work as an uplink for the data collected by the onboard sensors of the car. The car is expected to communicate with the drone which is flying in coordination. For the communication 868 MHz is selected to be used between the car and the drone. The test is performed to simulate different flight altitudes of drones. The signal strength of the communication is analyzed, and a model is developed which can be used for the future planning of the test track applications.