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Jozsef Rohacs
Department of Aeronautics and Naval Architecture, Budapest University of Technology and Economics, 1111 Budapest, Hungary

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Journal article
Published: 17 May 2021 in ISPRS International Journal of Geo-Information
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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.

ACS Style

Dinh Nguyen; Jozsef Rohacs; Daniel Rohacs. Autonomous Flight Trajectory Control System for Drones in Smart City Traffic Management. ISPRS International Journal of Geo-Information 2021, 10, 338 .

AMA Style

Dinh Nguyen, Jozsef Rohacs, Daniel Rohacs. Autonomous Flight Trajectory Control System for Drones in Smart City Traffic Management. ISPRS International Journal of Geo-Information. 2021; 10 (5):338.

Chicago/Turabian Style

Dinh Nguyen; Jozsef Rohacs; Daniel Rohacs. 2021. "Autonomous Flight Trajectory Control System for Drones in Smart City Traffic Management." ISPRS International Journal of Geo-Information 10, no. 5: 338.

Journal article
Published: 14 December 2020 in Applied Sciences
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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.

ACS Style

Dinh Dung Nguyen; József Rohács; Dániel Rohács; Anita Boros. Intelligent Total Transportation Management System for Future Smart Cities. Applied Sciences 2020, 10, 8933 .

AMA Style

Dinh Dung Nguyen, József Rohács, Dániel Rohács, Anita Boros. Intelligent Total Transportation Management System for Future Smart Cities. Applied Sciences. 2020; 10 (24):8933.

Chicago/Turabian Style

Dinh Dung Nguyen; József Rohács; Dániel Rohács; Anita Boros. 2020. "Intelligent Total Transportation Management System for Future Smart Cities." Applied Sciences 10, no. 24: 8933.

Journal article
Published: 09 December 2020 in Sustainability
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Numerous investigations assess the technical, technological, and managerial aspects of disaster response related to large technical systems. This paper deals with the possibility of synthesizing these aspects in a disaster response methodology, thus combining the technical, technological methods, tools, and software with the art of management. Its objective is to develop a preliminary methodology that supports the response management decision making processes related to earthquake-damaged large technical systems. The introduced methodology is demonstrated with the example of railway systems. It utilizes a combination of (i) a probabilistic model of railway system damage caused by earthquakes, (ii) a Markov model related to the damage and recovery phases, (iii) a probabilistic model of aftershocks, (iv) a statistical model of secondary effects, (v) impact models of management support actions, and (vi) response process management supported by a Markov Decision Process. The simulation results validate the concept. Based on these research results, the authors recommend that the described preliminary response management approach be further specified and implemented in disaster management procedures.

ACS Style

Sergey Kinzhikeyev; József Rohács; Dániel Rohács; Anita Boros. Sustainable Disaster Response Management Related to Large Technical Systems. Sustainability 2020, 12, 10290 .

AMA Style

Sergey Kinzhikeyev, József Rohács, Dániel Rohács, Anita Boros. Sustainable Disaster Response Management Related to Large Technical Systems. Sustainability. 2020; 12 (24):10290.

Chicago/Turabian Style

Sergey Kinzhikeyev; József Rohács; Dániel Rohács; Anita Boros. 2020. "Sustainable Disaster Response Management Related to Large Technical Systems." Sustainability 12, no. 24: 10290.

Journal article
Published: 19 August 2020 in Sensors
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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).

ACS Style

Utku Kale; József Rohács; Dániel Rohács. Operators’ Load Monitoring and Management. Sensors 2020, 20, 4665 .

AMA Style

Utku Kale, József Rohács, Dániel Rohács. Operators’ Load Monitoring and Management. Sensors. 2020; 20 (17):4665.

Chicago/Turabian Style

Utku Kale; József Rohács; Dániel Rohács. 2020. "Operators’ Load Monitoring and Management." Sensors 20, no. 17: 4665.

Journal article
Published: 13 May 2019 in Aircraft Engineering and Aerospace Technology
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PurposeThe purpose of this paper is to overview the systems and their elements developing for supporting the less-skilled pi-lots.Design/methodology/approachSeveral European (like EPATS, SAT-Rdmp, Pplane, Esposa, Clean Sky2) and national projects (NASA SATS, Hungarian SafeFly) develop the personal/small aircraft and personal/small aircraft transportation systems. The projects had analysed the safety aspects, too, and they underlined the aircraft will be controlled by so-called less-skilled pilots (owners, renters), having less experiences. The paper defines the cross-connected controls, introduces the methods of subjective analysis in pilot decision processes, improves the pilot workload model, defines the possible workload management and describes the developing pilot decision support system.FindingsAnalysing the personal/small aircraft safety aspects, a unique and important safety problem induced by less-skilled pilots has been identified. The considerable simplification of the air-craft control system, supporting the pilot subjective decisions and introducing the pilot work-load management, may eliminate this problem.Research limitations/implicationsOnly the system elements have been used in concept validation tests.Practical implicationsThe developing pilot supporting system in its general form has on - board and ground sub-systems, too, except a series of elements integrated into the pilot cockpit environment and control system. Several system elements (sensors, integrated controls, etc.) might be implement now, but the total system need further studies. The subjective decision process needs further development of the methodology and concept validation.Social implicationsThe system may catalyse the society acceptance of the personal aircraft and their safer piloting, applicability.Originality/valueThe paper introduces an original supporting system for less-skilled pilots.

ACS Style

Jozsef Rohacs; István Jankovics; Daniel Rohacs. Less-skilled pilot decision support. Aircraft Engineering and Aerospace Technology 2019, 91, 790 -802.

AMA Style

Jozsef Rohacs, István Jankovics, Daniel Rohacs. Less-skilled pilot decision support. Aircraft Engineering and Aerospace Technology. 2019; 91 (5):790-802.

Chicago/Turabian Style

Jozsef Rohacs; István Jankovics; Daniel Rohacs. 2019. "Less-skilled pilot decision support." Aircraft Engineering and Aerospace Technology 91, no. 5: 790-802.

Preprint
Published: 22 August 2018
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Nowadays, all the stakeholders, policy makers, regulators, aircraft designers, producers, operators, etc.) are intensively working on development of the aircraft with full electric and hybrid propulsion systems. However, the technical, technological constrains (like limit on accumulator energy density) require introducing a new approach to conceptual design of such aircraft. The new methods is based on energy and mass balance evaluation. This paper analyses the identified constrains; integrates the energy and mass balance equations into the preliminary definition and calculations of the aircraft performance. By this way, the technological constrains might be transferred into the limitation on the aircraft energy and mass breakdown, that initiates a new approach to aircraft conceptual design uses the knowledge based multidisciplinary optimization. The paper describes the developed methodology for conceptual design of aircraft. It show results of implementing this new development philosophy to conceptual design of a four-seat small electric/hybrid aircraft and a special hybrid cargo UAV. The discussion of the results including got by using the emerging and enabling new technologies and new methods and solutions (including for example distributed propulsion system, unconventional forms, morphing, biomimics, etc.), demonstrates the possible implementation of the new development philosophy, new approach to aircraft conceptual design.

ACS Style

Jozsef Rohacs; Daniel Rohacs. Effect of Energy Balance Evaluation on Conceptual Design of Electric and Hybrid Aircraft. 2018, 1 .

AMA Style

Jozsef Rohacs, Daniel Rohacs. Effect of Energy Balance Evaluation on Conceptual Design of Electric and Hybrid Aircraft. . 2018; ():1.

Chicago/Turabian Style

Jozsef Rohacs; Daniel Rohacs. 2018. "Effect of Energy Balance Evaluation on Conceptual Design of Electric and Hybrid Aircraft." , no. : 1.

Journal article
Published: 01 January 2018 in Journal of Transportation Technologies
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Nowadays, the success of the new technology development and deployment process depends not only on technical, technological solutions, but also on solving the non-technological problems and crossing the societal and psychological barriers. A large international European projects, GABRIEL1 had developed a maglev assisted aircraft take-off and landing, that was applied to conceptual design of aircraft and required on-board and ground systems, had analysed all impacts (effects of concept deployment on effectiveness, safety, security, noise, emissions) and had demonstrated the safe applicability by concept validation. The applied methodology, used methods and the results of the Gabriel projects had been described and discussed by 55 project deliverables. This paper has a special goal: investigating the problems and barriers of possible implementing of the radically new technology, aircraft MagLev assisted take-off and landing. The study was started by identification and classification of the problems and barriers. After it, the problems were systematically analysed by use of special methodology containing the understanding (description) of the problems, investigation of the possible solutions and discussing their applicability (mainly by use of the Gabriel project results). The paper has three major sections: 1) description of the Gabriel concept and project results, 2) introducing some related thoughts on general aspects of new technology developments, and 3) discussion on the problems and their solutions. The major classes of the problems are the 1) technical, technological problems as developing a radically new solution, landing the undercarriage-less aircraft on the magnetic tracks, 2) stakeholders’ problems as decision makers kicking against supporting the developments of so radically new technologies and 3) society barriers like society worrying on and fear of future passengers on flying by aircraft have not conventional undercarriage systems. The paper will show that these problems have safe and cost-effective solutions.

ACS Style

Jozsef Rohacs; Daniel Rohacs. Problems and Barriers Impeding the Implementation of MagLev Assisted Aircraft Take-Off and Landing Concept. Journal of Transportation Technologies 2018, 08, 91 -118.

AMA Style

Jozsef Rohacs, Daniel Rohacs. Problems and Barriers Impeding the Implementation of MagLev Assisted Aircraft Take-Off and Landing Concept. Journal of Transportation Technologies. 2018; 08 (02):91-118.

Chicago/Turabian Style

Jozsef Rohacs; Daniel Rohacs. 2018. "Problems and Barriers Impeding the Implementation of MagLev Assisted Aircraft Take-Off and Landing Concept." Journal of Transportation Technologies 08, no. 02: 91-118.

Journal article
Published: 01 August 2016 in Progress in Aerospace Sciences
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The Technology Roadmap 2013 developed by the International Air Transport Association envisions the option of flying without an undercarriage to be in operation by 2032. Preliminary investigations clearly indicate that magnetic levitation technology (MagLev) might be an appealing solution to assist the aircraft take-off and landing. The EU supported research project, abbreviated as GABRIEL, was dealing with (i) the concept development, (ii) the identification, evaluation and selection of the deployable magnetic levitation technology, (iii) the definition of the core system elements (including the required aircraft modifications, the ground-based system and airport elements, and the rendezvous control system), (iv) the analysis of the safety and security aspects, (v) the concept validation and (vi) the estimation of the proposed concept impact in terms of aircraft weight, noise, emission, cost-benefit). All results introduced here are compared to a medium size hypothetic passenger aircraft (identical with an Airbus A320). This paper gives a systematic overview of (i) the applied methods, (ii) the investigation of the possible use of magnetic levitation technology to assist the commercial aircraft take-off and landing processes and (iii) the demonstrations, validations showing the feasibility of the radically new concept. All major results are outlined.

ACS Style

Daniel Rohacs; Jozsef Rohacs. Magnetic levitation assisted aircraft take-off and landing (feasibility study – GABRIEL concept). Progress in Aerospace Sciences 2016, 85, 33 -50.

AMA Style

Daniel Rohacs, Jozsef Rohacs. Magnetic levitation assisted aircraft take-off and landing (feasibility study – GABRIEL concept). Progress in Aerospace Sciences. 2016; 85 ():33-50.

Chicago/Turabian Style

Daniel Rohacs; Jozsef Rohacs. 2016. "Magnetic levitation assisted aircraft take-off and landing (feasibility study – GABRIEL concept)." Progress in Aerospace Sciences 85, no. : 33-50.

Journal article
Published: 29 April 2014 in Aircraft Engineering and Aerospace Technology
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ACS Style

József Rohács; Daniel Rohacs. The potential application method of magnetic levitation technology – as a ground-based power – to assist the aircraft takeoff and landing processes. Aircraft Engineering and Aerospace Technology 2014, 86, 188 -197.

AMA Style

József Rohács, Daniel Rohacs. The potential application method of magnetic levitation technology – as a ground-based power – to assist the aircraft takeoff and landing processes. Aircraft Engineering and Aerospace Technology. 2014; 86 (3):188-197.

Chicago/Turabian Style

József Rohács; Daniel Rohacs. 2014. "The potential application method of magnetic levitation technology – as a ground-based power – to assist the aircraft takeoff and landing processes." Aircraft Engineering and Aerospace Technology 86, no. 3: 188-197.