The Experts below are selected from a list of 13041 Experts worldwide ranked by ideXlab platform
Yasin Korkmaz - One of the best experts on this subject based on the ideXlab platform.
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Computation of the pressure altitude using adaptive neuro fuzzy inference system for Air Data Computer in aircrafts
2011 IEEE 19th Signal Processing and Communications Applications Conference (SIU), 2011Co-Authors: Ilke Turkmen, Yasin KorkmazAbstract:For a Safe Flight and accurate air navigation, the key data are calculated using Air Data Computer (ADC). Altitude information is one of the important parameter computed by the ADC. According to aircraft type, accuracy of the altitude corrected using tables or charts showing the actual corrections in altitude information special to the aircraft. This correction is important in any high performance and jet aircraft. In this paper, adaptive neuro fuzzy system (ANFIS) are used to calculate altitude information more easily and accurately using data obtained from tables formed under standard atmosphere conditions. The pressure altitude values obtained using proposed ANFIS model don't need to correction.
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Uçaklardaki Hava Veri Bilgisayarinda Basinç İrtifasinin Bulanik Mantik Sistemine Dayali Uyarlanir Ağ İle Hesaplanmasi Computation of the Pressure Altitude Using Adaptive Neuro Fuzzy Inference System for Air Data Computer in Aircrafts
2011Co-Authors: Yasin KorkmazAbstract:For a Safe Flight and accurate air navigation, the key data are calculated using Air Data Computer (ADC). Altitude information is one of the important parameter computed by the ADC. According to aircraft type, accuracy of the altitude corrected using tables or charts showing the actual corrections in altitude information special to the aircraft. This correction is important in any high performance and jet aircraft. In this paper, adaptive neuro fuzzy system (ANFIS) are used to calculate altitude information more easily and accurately using data obtained from tables formed under standard atmosphere conditions. The pressure altitude values obtained using proposed ANFIS model don’t need to correction. 1. GIRIŞ
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the pressure altitude computation using artificial neural network for air data computer
International Symposium on Signal Processing and Information Technology, 2010Co-Authors: Ilke Turkmen, Yasin KorkmazAbstract:Air Data Computer (ADC) calculates the key data necessary for performing a Safe Flight and accurate air navigation. Altitude information is one of the important parameter computed by the ADC. Accuracy of the altitude corrected using tables or charts showing the actual corrections in altitude information special to aircraft type. This correction is important in any high performance and jet aircraft. In order to correct these imperfections, certain calibrations need to be made within the ADC. In this paper, artificial neural networks (ANNs) are used to calculate altitude information more easily and accurately using data obtained from tables formed under standard atmosphere conditions.
Stuart Galloway - One of the best experts on this subject based on the ideXlab platform.
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fault classification and diagnostic system for unmanned aerial vehicle electrical networks based on hidden markov models
IET electrical systems in transportation, 2015Co-Authors: Rory Telford, Stuart GallowayAbstract:In recent years there has been an increase in the number of unmanned aerial vehicle (UAV) applications intended for various missions in a variety of environments. The adoption of the more-electric aircraft has led to a greater emphasis on electrical power systems (EPS) for Safe Flight through an increased number of critical loads being sourced with electrical power. Despite extensive literature detailing the development of systems to detect UAV failures and enhance overall system reliability, few have focussed directly on the increasingly complex and dynamic EPS. This study outlines the development of a novel UAV EPS fault classification and diagnostic (FCD) system based on hidden Markov models (HMM) that will assist and improve EPS health management and control. The ability of the proposed FCD system to autonomously detect, classify and diagnose the severity of diverse EPS faults is validated with development of the system for NASA's advanced diagnostic and prognostic testbed (ADAPT), a representative UAV EPS system. EPS data from the ADAPT network was used to develop the FCD system and results described within this study show that a high classification and diagnostic accuracy can be achieved using the proposed system.
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evaluating the reliability availability of more electric aircraft power systems
International Universities Power Engineering Conference, 2012Co-Authors: R. D. Telford, Stuart Galloway, Graeme BurtAbstract:With future aircraft designs increasingly embracing the more-electric concept, there is likely to be a greater reliance on electrical systems for Safe Flight. More-electric aircraft (MEA) will have a greater number of electrical loads which are critical to the aircraft Flight. It therefore is essential that the design of aircraft power systems embraces new technologies and methods in order to achieve targets for aircraft certification. The various design drivers (e.g. weight, space) for aircraft will also have to be considered when incorporating reliability into future MEA. This paper will investigate options for future platforms to meet reliability and availability targets whilst continuing to improve overall efficiency. The paper proposes a software tool that has the ability to determine the reliability of a number of potential alternative design architectures. This paper outlines present designs of such systems and how reliability is enhanced through the use of redundancy and back-up generation. The regulatory challenges associated with aircraft are summarised, including a discussion on reliability targets for various loads. Techniques for assessing the reliability of aircraft systems are described and simple examples of their application to aircraft electrical systems are provided. These examples will highlight the advantages and drawbacks attributed to each method and the reasoning behind the selection of these techniques on which an analysis tool can be based.
De Visser C.c. - One of the best experts on this subject based on the ideXlab platform.
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Database-driven Safe Flight Envelope Protection for Impaired Aircraft
'American Institute of Aeronautics and Astronautics (AIAA)', 2020Co-Authors: Zhang Y., Chu Q. P., Huang Y., De Visser C.c.Abstract:In this paper, an online Flight envelope protection system is developed and implemented on impaired aircraft with structural damage. The whole protection system is designed to be a closed-loop of several sub-systems, including system identification, damage classification, Flight-envelope prediction and fault-tolerant control. Based on the information given by damage classification, the Flight envelopes are explicitly retrieved and processed online from the database and fed into the fault-tolerant controller, which makes the protection system adaptive to a wide range of abnormal conditions. Simulation results show that with envelope protection, loss-of-control accidents are more likely to be prevented, since both the controller and pilots are aware of the shrunken Flight envelopes after damage and excessive commands are restricted. In this way, the fault-tolerance of the impaired aircraft can be effectively enhanced.Control & Simulatio
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Effects of structural failure on the Safe Flight envelope of aircraft
2018Co-Authors: Nabi H.n., Zhang Y., Lombaerts T.j.j., Van Kampen E., Chu Q., De Visser C.c.Abstract:The research presented in this paper focuses on the effects of structural failures on the Safe Flight envelope of an aircraft, which is the set of all the states in which Safe maneuver of the aircraft can be assured. Nonlinear reachability analysis basedonan optimal control formulation is performed to estimate the Safe Flight envelope using actual aircraft control surface inputs. This approach uses the physical model of an aircraft, where the aerodynamic stability and control derivatives are calculated using Digital Datcom. Symmetrical damages to a Cessna Citation II are considered with 25, 50, 75, and 100% spanwise vertical tail tip losses, leading to gradual shrinkage in the Safe Flight envelope. Based on the estimated Safe Flight envelopes, a discussion on the effects of structural damages and different Flight conditions on the Safe Flight envelope is presented. In particular, the interpolatibility of the resulting Safe Flight envelopes is demonstrated. This property is essential for a novel database-driven Flight envelope prediction method, where a database of Safe Flight envelopes is created offline to be accessed later in real time.
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Effects of structural failure on the Safe Flight envelope of aircraft
'American Institute of Aeronautics and Astronautics (AIAA)', 2018Co-Authors: Nabi H.n., Zhang Y., Lombaerts T.j.j., Van Kampen E., Chu Q., De Visser C.c.Abstract:The research presented in this paper focuses on the effects of structural failures on the Safe Flight envelope of an aircraft, which is the set of all the states in which Safe maneuver of the aircraft can be assured. Nonlinear reachability analysis basedonan optimal control formulation is performed to estimate the Safe Flight envelope using actual aircraft control surface inputs. This approach uses the physical model of an aircraft, where the aerodynamic stability and control derivatives are calculated using Digital Datcom. Symmetrical damages to a Cessna Citation II are considered with 25, 50, 75, and 100% spanwise vertical tail tip losses, leading to gradual shrinkage in the Safe Flight envelope. Based on the estimated Safe Flight envelopes, a discussion on the effects of structural damages and different Flight conditions on the Safe Flight envelope is presented. In particular, the interpolatibility of the resulting Safe Flight envelopes is demonstrated. This property is essential for a novel database-driven Flight envelope prediction method, where a database of Safe Flight envelopes is created offline to be accessed later in real time.Control & SimulationWind Energ
Nora Ayanian - One of the best experts on this subject based on the ideXlab platform.
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Trajectory Planning for Quadrotor Swarms
IEEE Transactions on Robotics, 2018Co-Authors: Wolfgang Honig, James A. Preiss, T. K. Satish Kumar, Nora AyanianAbstract:—We describe a method for multi-robot trajectory planning in known, obstacle-rich environments. We demonstrate our approach on a quadrotor swarm navigating in a warehouse setting. Our method consists of three stages: 1) roadmap gener-ation which generates sparse roadmaps annotated with possible inter-robot collisions; 2) discrete planning which finds valid execution schedules in discrete time and space; and 3) contin-uous refinement that creates smooth trajectories. We account for the downwash effect of quadrotors, allowing Safe Flight in dense formations. We demonstrate computational efficiency in simulation with up to 200 robots and physical plausibility with an experiment on 32 nano-quadrotors. Our approach can compute Safe and smooth trajectories for hundreds of quadrotors in dense environments with obstacles in a few minutes.
Peng Wang - One of the best experts on this subject based on the ideXlab platform.
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Safety Assessment of the Reconfigurable Integrated Modular Avionics Based on STPA
'Hindawi Limited', 2021Co-Authors: Changxiao Zhao, Lei Dong, Peng WangAbstract:The reconfiguration technology, which is the significant feature of the newly designed Integrated Modular Avionics (IMA) system, enables the transfer of avionics functions from the failed module to the residual normal module, thereby enhancing the robustness of the whole system. The basic target of the IMA reconfiguration is to ensure the Safe Flight and correct execution of the mission. To solve the problem of lack of effective management mechanism for the IMA system development and Safety assessment, a Safety analysis method based on STAMP/STPA and UPPAAL for IMA reconfiguration is proposed. The method focuses mainly on system characteristics and multiparty interactions. On the basis of this approach, some studies and analyses have been carried out. Firstly, the STAMP/STPA principle is studied and used to identify unSafe control actions in the reconfiguration process. Secondly, a formal model of IMA reconfiguration is developed using UPPAAL. Finally, the accessibility analysis of the formal model is used to analyze UCAs and the corresponding loss scenarios. The method enables a detailed description of the interactions between the components and a rigorous mathematical analysis of the system, thereby diluting the effect of human factors while ensuring the accuracy and reliability of the Safety constraints
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systematic reliability modeling and evaluation for on board power systems of more electric aircrafts
IEEE Transactions on Power Systems, 2019Co-Authors: Tianyang Zhao, Peng WangAbstract:Modern aircrafts are evolving toward more electric aircraft (MEA), resulting in greater reliance on the electrical system for Safe Flight. On-board power system of MEA integrates a large number of power electronic converters, and it is reported that semiconductor devices and electrolytic capacitors in power converters are the most vulnerable links impacted by loading conditions; thus, reliability becomes a critical concern in an MEA power system. This paper proposes a hierarchical approach for systematic reliability modeling and evaluation for the on-board power system of MEAs. It consists of three hierarchical levels (HLs): component level (HL1), subsystem level (HL2), and system level (HL3). In HL1, failure rates of power electronic components are modeled considering relevant inner structure and loading conditions; in HL2, the reliability of individual subsystems such as converters are constructed; in HL3, the system reliability is quantified based on the network architecture and reliability of the subsystems. The impacts of different parts (components/subsystems) on the overall system are assessed effectively with the identification of the vulnerable parts. This also provides a guideline for reliability enhancement by using thermal control techniques, adding redundancies or performing maintenance on the vulnerable parts to ensure the satisfactory of system reliability requirements. The proposed method is demonstrated on the future MEA power system architectures (hybrid ac–dc architecture and HVdc architecture).
