102,004 research outputs found
Electro-Mechanical Actuators for the More Electric Aircraft (Fault diagnosis and condition monitoring approaches)
No full textThis chapter presents the basic concepts of condition monitoring and fault diagnosis, with special attention to the definition of terminology and design approaches. Actually, the terminology in the field is not consistent, since it often depends on research context, application, and publication period. The concepts of fault detection, fault isolation, fault identification, fault estimation are systematically presented and clarified, with precise definitions of fault, malfunction, failure, residual, disturbance, and error. The specificities of condition monitoring and fault diagnosis are highlighted, and the various approaches to implement them are discussed
Electro-Mechanical Actuators for the More Electric Aircraft (Introduction)
No full textThis chapter presents the motivations behind the more electric aircraft initiative, with a focus on technological, environmental, societal, and market aspects. The main trends in the development of electrically powered systems for aerospace applications are highlighted, with particular attention to actuation systems. Finally, the state of the art of electro-mechanical actuation systems in aircraft is presented, by describing the design solutions used for their employment in flight controls, landing gears, nose-wheel steering, thrust vectoring control, brakes, and innovative applications
Electro-Mechanical Actuators for the More Electric Aircraft (Reliability and safety of electro-mechanical actuators for aircraft applications)
No full textThis chapter presents the basic reliability and safety concerns related to the development of airborne Electro-Mechanical Actuators (EMAs), which typically imply the necessity of redundant architectures for obtaining flightworthy solutions. The standard guidelines and procedures for the System Safety Assessment of airborne systems are presented, highlighting the methodical approach to be carried out throughout the systems’ design and testing. A practical example of Preliminary System Safety Assessment is also given, with reference to the electro-mechanical actuation system of the morphing flaps of a more electric aircraft demonstrator
Electro-Mechanical Actuators for the More Electric Aircraft
No full textThis book presents recent results on fault diagnosis and condition monitoring of airborne electromechanical actuators, illustrating both algorithmic and hardware design solutions to enhance the reliability of onboard more electric aircraft.
The book begins with an introduction to the current trends in the development of electrically powered actuation systems for aerospace applications. Practical examples are proposed to help present approaches to reliability, availability, maintainability and safety analysis of airborne equipment. The terminology and main strategies for fault diagnosis and condition monitoring are then reviewed. The core of the book focuses on the presentation of relevant case studies of fault diagnosis and monitoring design for airborne electromechanical actuators, using different techniques. The last part of the book is devoted to a summary of lessons learned and practical suggestions for the design of fault diagnosis solutions of complex airborne systems.
The book is written with the idea of providing practical guidelines on the development of fault diagnosis and monitoring algorithms for airborne electromechanical actuators. It will be of interest to practitioners in aerospace, mechanical, electronic, reliability and systems engineering, as well as researchers and postgraduates interested in dynamical systems, automatic control and safety-critical systems
Electro-Mechanical Actuators for the More Electric Aircraft (Concluding remarks)
No full textThis chapter summarizes the contributions presented in the previous chapters of the book, highlighting the main lessons learned during the development of the presented projects. Furthermore, the chapter presents an overview of other existing fault diagnosis projects in aerospace electro-mechanical actuators, ending with suggestions for future work
Electro-Mechanical Actuators for the More Electric Aircraft (Fault diagnosis and condition monitoring of aircraft electro-mechanical actuators)
No full textThis chapter presents a selection of fault diagnosis problems related to airborne Electro-Mechanical Actuators (EMAs). First, the chapter presents the motivations underlying the R&D efforts dedicated to fault diagnosis in the aerospace sector. Then, several real-world applications for flight EMAs are presented and discussed, with reference to both the research and industry sectors. Specifically, the attention is focused on: (i) the European FP7 HOLMES project, dealing with fault detection of secondary flight control actuators; (ii) the European H2020 REPRISE project, aimed at condition monitoring of primary flight control actuators; (iii) fault detection and fault prognosis of primary flight control actuators for unmanned aerial vehicles. Finally, solutions to the presented monitoring problems are provided by applying techniques that range from model-based to signal-based and knowledge-based fault diagnosis approaches
A robust design strategy for stock trading via feedback control
No full textThe main objective of equity traders is to find a trading law leading to a safe profit, whatever the dynamics of the price be. Recenlty, a novel approach based on feedback control has been proposed, which allows the trader to treat the price as an exogenous disturbance to reject, rather than a stochastic process to be modelled. Although very promising, some questions arise, among which how to design the feedback controller defining the trading policy. In this work, we propose a reformulation of feedback trading as a trend following robust control problem, in which mild knowledge on the price range is exploited. The proposed approach is shown to outperform the state of the art methods on real-world stocks
Stock trading via feedback control: an extremum seeking approach
No full textIn finance, the goal of technical analysis is to model stock dynamics to make reliable predictions of future prices. In recent years, Prof. B. Barmish and coauthors have proposed a paradigm shift in which stock trading is reformulated as a control design problem. From such a perspective, unpredictable price variations can be seen as external disturbances and do not need to be accurately modeled for the investment policy to be properly selected. Although very powerful, the tuning of the reactive scheme to stock trading is all but straightforward. In this paper, an Extremum Seeking approach is proposed to directly design the control action from data and make the overall strategy adaptive with respect to trend variations of the stock price. The method is extensively backtested on real stock data
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