Aircraft electrification is one of the most important and strategic initiatives currently supporting the innovation of the aviation industry. This manifests in the well-known more-electric aircraft concept (with the ultimate aim of achieving the all-electric long-term target), which aims to gradually replace onboard systems based on mechanical, hydraulic, or pneumatic power sources with electrically powered ones to reduce the weight and costs, optimize energy, and increase the eco-compatibility and reliability of future aircrafts. A key technological enabler for pursuing these challenging objectives is electro-mechanical actuation. The applicability of electro-mechanical actuators (EMAs) in aerospace has been proved in terms of dynamic performances, but it still entails several concerns in terms of reliability/safety and operation in a harsh environment. In civil aircrafts, EMAs are often avoided for safety-critical functions (flight controls, brakes, landing gears, and nose wheel steering), essentially because the statistical database on the components' fault modes is poor. This Special Issue is thus focused on advancements and innovations in the design, modelling/simulation, architectural definition, reliability/safety analysis, control, condition-monitoring, and experimental testing of EMAs developed for safety-critical aerospace applications. The research papers included in this Special Issue will undoubtedly contribute to progress towards the objective of more electric flights.
This 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. Advances in Industrial Control reports and encourages the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.
This 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. Advances in Industrial Control reports and encourages the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.
Reducing the power consumptionand hence, the fuel burnis a major target for the next generation of aircraft, and electrical actuation is perceived as a technological area able to provide power saving. Electrical actuation can in fact contribute to the reduction of the non-propulsive power because electro-mechanical actuators, when compared to the conventional hydraulic actuators, rely on a form of power subjected to lower distribution losses and in general can lead to a weight savings at the aircraft level if the required power remains under a break-over point. Moreover, electro-mechanical actuators (EMAs) present higher reliability and maintainability with a lower life-cycle cost.Two critical issues with electrically powered actuation are the temperature rise in the electric motor windings and in the power electronics, and the sensitivity to certain single point of failures that can lead to mechanical seizures, that has so far thwarted the use of EMAs for safety-critical applications. In order to address the issue of a possible actuator seizure, many research and development activities have been performed to identify ways of making an electro-mechanical actuator jam-free or jam-tolerant, since this would allow more flexibility in defining the overall architecture of the flight control system. Although interesting and ingenious design solutions have been proposed, they all have so far resulted in complex mechanical designs that on one hand allow the actuator to operate after a jam of an internal component, but on the other hand bring about increased weight, volume, and cost, and a reliability reduction due to the much larger number of parts.With primary flight control actuators being some of the more safety-critical components of an aircraft, an undetected actuator failure can lead to serious consequences. Furthermore, failures that are not flight safety critical can still have negative consequences ranging from flight disruptions to unscheduled and costly maintenance.The development of an effective and reliable PHM system for EMAs is thus seen as a possible way to contribute to the acceptance of EMAs as primary flight control actuators in commercial aircraft, for an effective PHM system will feature appropriate diagnostic functions to detect anomalous behavior, and prognostic capabilities indicating when an incipient fault develops and estimating how, under continuing usage, the fault will eventually become a failure. Providing EMAs with a PHM capability will entail positive results in different areas: Progressively improve the EMA robustness; PHM algorithms can initially provide indication of the onset of a fault, while more sophisticated reasoning functions can then assess the remaining useful life and contribute to the safety of flight. Minimize the unscheduled maintenance events, thereby increasing the EMA availability. Facilitate maintenance operations and troubleshooting. Simplify the supply chain.It is important to note that a more extensive use of EMAs facilitated by PHM algorithms must be associated to all design provisions necessary to attain mandatory safety requirements. Electro-mechanical actuators (EMAs) are used in different aerospace applications performing functions with different degrees of criticality, and a trend exists to progressively replace hydraulic actuators with EMAs for most flight-critical applications. This carries along a growing interest in providing EMAs with a prognostics and health management (PHM) system allowing effective diagnostics, prognostics, and recovery actions. Early fault detection is needed in flight-critical applications to allow enough time for contingency management in order to avoid the occurrence of safety-critical situations.The development of an EMA PHM system is a challenging task since EMAs are complex systems made up by electronic, electrical, and mechanical subsystems, and are typically under-instrumented. This implies that a fault in an EMA component may have effects on other parts of the actuator, which makes it difficult to successfully identify and isolate the fault, especially when only a limited number of signals is available.The purpose of this document is to provide the guidelines of the technological approach for developing a PHM system for EMAs with particular reference to their possible use as primary flight control actuators. It provides a basic description of the physics of the most common degradation processes, a reliability assessment, and a discussion on the signals, with the associated data processing, required to build up an effective health monitoring system.
This Aerospace Recommended Practice (ARP) provides general characteristics, requirements, and design data to be recommended for inclusion in a procurement technical specification of an electromechanical actuator (EMA), including its control and monitoring. As electromechanical actuators (EMAs) are being more frequently used for safety critical aerospace applications, there is a need for a document providing comprehensive guidelines for specifying their design requirements. This document meets this need.
This book is the second in a series of volumes which cover the topic of aerospace actuators following a systems-based approach. This second volume brings an original, functional and architectural vision to more electric aerospace actuators. The aspects of signal (Signal-by-Wire) and power (Power-by-Wire) are treated from the point of view of needs, their evolution throughout history, and operational solutions that are in service or in development. This volume is based on an extensive bibliography, numerous supporting examples and orders of magnitude which refer to flight controls and landing gear for various aircraft (fixed or rotorwing, launchers) in commercial, private and military applications. The topics covered in this set of books constitute a significant source of information for individuals and engineers from a variety of disciplines, seeking to learn more about aerospace actuation systems and components.
Airworthiness, as a field, encompasses the technical and non-technical activities required to design, certify, produce, maintain, and safely operate an aircraft throughout its lifespan. The evolving technology, science, and engineering methods and, most importantly, aviation regulation, offer new opportunities and create, new challenges for the aviation industry. This book assembles review and research articles across a variety of topics in the field of airworthiness: aircraft maintenance, safety management, human factors, cost analysis, structures, risk assessment, unmanned aerial vehicles and regulations. This selection of papers informs the industry practitioners and researchers on important issues.
This book is the second in a series of volumes which cover the topic of aerospace actuators following a systems-based approach. This second volume brings an original, functional and architectural vision to more electric aerospace actuators. The aspects of signal (Signal-by-Wire) and power (Power-by-Wire) are treated from the point of view of needs, their evolution throughout history, and operational solutions that are in service or in development. This volume is based on an extensive bibliography, numerous supporting examples and orders of magnitude which refer to flight controls and landing gear for various aircraft (fixed or rotorwing, launchers) in commercial, private and military applications. The topics covered in this set of books constitute a significant source of information for individuals and engineers from a variety of disciplines, seeking to learn more about aerospace actuation systems and components.
Aerospace vehicles are by their very nature a crucial environment for safety-critical systems. By virtue of an effective safety control system, the aerospace vehicle can maintain high performance despite the risk of component malfunction and multiple disturbances, thereby enhancing aircraft safety and the probability of success for a mission. Autonomous Safety Control of Flight Vehicles presents a systematic methodology for improving the safety of aerospace vehicles in the face of the following occurrences: a loss of control effectiveness of actuators and control surface impairments; the disturbance of observer-based control against multiple disturbances; actuator faults and model uncertainties in hypersonic gliding vehicles; and faults arising from actuator faults and sensor faults. Several fundamental issues related to safety are explicitly analyzed according to aerospace engineering system characteristics; while focusing on these safety issues, the safety control design problems of aircraft are studied and elaborated on in detail using systematic design methods. The research results illustrate the superiority of the safety control approaches put forward. The expected reader group for this book includes undergraduate and graduate students but also industry practitioners and researchers. About the Authors: Xiang Yu is a Professor with the School of Automation Science and Electrical Engineering, Beihang University, Beijing, China. His research interests include safety control of aerospace engineering systems, guidance, navigation, and control of unmanned aerial vehicles. Lei Guo, appointed as "Chang Jiang Scholar Chair Professor", is a Professor with the School of Automation Science and Electrical Engineering, Beihang University, Beijing, China. His research interests include anti-disturbance control and filtering, stochastic control, and fault detection with their applications to aerospace systems. Youmin Zhang is a Professor in the Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, Québec, Canada. His research interests include fault diagnosis and fault-tolerant control, and cooperative guidance, navigation, and control (GNC) of unmanned aerial/space/ground/surface vehicles. Jin Jiang is a Professor in the Department of Electrical & Computer Engineering, Western University, London, Ontario, Canada. His research interests include fault-tolerant control of safety-critical systems, advanced control of power plants containing non-traditional energy resources, and instrumentation and control for nuclear power plants.
