1,721,026 research outputs found
Closed Loop Control of FES Supported Standing Up and Sitting Down Using Virtual Reference Feedback Tuning: a simulation study
No full textElectro-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
Classification algorithms analysis for brain–computer interface in drug craving therapy
No full textThis paper presents a novel therapy to recover patients from drug craving diseases, with the use of brain–computer interfaces (BCIs). The clinical protocol consists of trying to mentally repel drug-related images, and a Stroop test is used to evaluate the blue therapy effect. The method requires a BCI hardware package and a software program which communicates with the device. In order to improve the BCI detection rates, data were collected from five different healthy subjects during the training. These measurements are then used to design a better classification algorithm with respect to the default BCI classifier. The investigated algorithms are logistic regression, support vector machines, decision trees, k-nearest neighbors and Naive Bayes. Although the low number of participants is not enough to guarantee statistically significant results, the designed algorithms perform better than the default one, in terms of accuracy, F1-score and area under the curve (AUC). The Naive Bayes method has been chosen as the best classifier between the tested ones, giving a +12.21% performance boost as concerns the F1-score metric. The presented methodology can be extended to other types of craving problems, such as food, pornography and alcohol. Results relative to the effectiveness of the proposed approach are reported on a set of patients with drug craving problems
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
Identification of nonlinear dynamical system with synthetic data: a preliminary investigation
No full textThis paper introduces a new rationale for learning nonlinear dynamical systems. The method makes use of an additional identification dataset, obtained without performing a new experiment on the system under study. The data are generated in an automatical manner, starting from a set of experimentally acquired measurements. In order to leverage the additional generated information, fundamental techniques from the machine learning field known as Semi-Supervised Learning (SSL) are employed and adapted. The problem is then cast as a regularized parametric learning problem. The effectiveness of the proposed approach is assessed on various nonlinear benchmark systems via repeated simulations, comparing the obtained results with a standard regularization method for learning parametric models. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
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