Electro-Mechanical Actuators for the More Electric Aircraft

Series Editor’s Foreword
Preface
Contents
Abbreviations
1 Introduction
	1.1 Electrification of Onboard Power Systems: The ``More Electric Aircraft'' Concept
		1.1.1 Technological Issues
		1.1.2 Environmental and Societal Issues
		1.1.3 Market Issues
	1.2 Impacts of Research and Development of Electro-Mechanical Actuators
		1.2.1 Electrically Powered Actuators
		1.2.2 EMA Technology
		1.2.3 EMA Research
	1.3 State of the Art of Aircraft EMA Technologies
		1.3.1 Flight Controls
		1.3.2 Landing Gears
		1.3.3 Nose-Wheel Steering
		1.3.4 Brakes
		1.3.5 Thrust Vectoring Control
		1.3.6 Innovative Functions
	1.4 Summary
	References
2 Reliability and Safety of Electro-Mechanical Actuators  for Aircraft Applications
	2.1 Basic Reliability and Safety Concerns
		2.1.1 Fault Regimes of Airborne Components
		2.1.2 Airworthiness Certification Requirements
		2.1.3 Hardware Redundancy
		2.1.4 Analytical Redundancy
	2.2 Fault-Tolerant Electro-Mechanical Actuator Solutions
		2.2.1 Fault-Tolerant Electronics
		2.2.2 Fault-Tolerant Motors
		2.2.3 Jamming-Tolerant Mechanical Transmissions
	2.3 Approach to the System Safety Assessment
		2.3.1 Guidelines, Methods, and Procedures
		2.3.2 Functional Hazard Assessment
		2.3.3 Fault-Tree Analysis
		2.3.4 Failure Mode, Effects, and Criticality Analysis
		2.3.5 Built-in Tests
		2.3.6 Types and Terminology of EMA Faults
	2.4 Preliminary System Safety Assessment of an Electro-Mechanical Actuation System for Morphing Flaps
		2.4.1 System Description
		2.4.2 Operation Modes
		2.4.3 Definition and Allocation of the Functional Requirements
		2.4.4 Functional Hazard Analysis
		2.4.5 Fault-Tree Analysis
	2.5 Summary
	References
3 Fault Diagnosis and Condition Monitoring Approaches
	3.1 Basic Concepts and Terminology
		3.1.1 Fault, Failure, Malfunction, Disturbance, Model Uncertainty
		3.1.2 Fault Diagnosis, Condition Monitoring, and Fault Prognosis
		3.1.3 Fault-Tolerant Systems
	3.2 Common Diagnostic Methodologies
		3.2.1 Model-Based Approach
		3.2.2 Signal-Based Approach
		3.2.3 Knowledge-Based Approach
		3.2.4 Hybrid Approach
		3.2.5 Active Approach
	3.3 State-of-the-Art of Monitoring Approaches for Airborne Electro-Mechanical Actuators and Systems
	3.4 Summary
	References
4 Fault Diagnosis and Condition Monitoring of Aircraft Electro-Mechanical Actuators
	4.1 Considerations and Challenges
	4.2 Relevant Recent Aerospace Projects
		4.2.1 FP7 HOLMES Project
		4.2.2 H2020 REPRISE Project: Phase 1
		4.2.3 H2020 REPRISE Project: Phase 2
		4.2.4 Primary Flight Control Electro-Mechanical Actuator for Medium Altitude Long Endurance Unmanned Aerial Vehicle
	4.3 Model-Based Approaches
		4.3.1 Fault Diagnosis via Real-Time Executable Models
		4.3.2 Fault Prognosis via High-Fidelity Dynamic Models
		4.3.3 Fault Diagnosis via High-Fidelity Dynamic Models
		4.3.4 Final Considerations on Model-Based Approaches
	4.4 Signal-Based Approaches
		4.4.1 Common Faults in Electro-Mechanical Actuators Diagnosable by Signal-Based Approaches
		4.4.2 Example: Fault Detection and Isolation of Bearing Defects
		4.4.3 Final Considerations on Signal-Based Approaches
	4.5 Knowledge-Based Approaches
		4.5.1 Knowledge-Based Fault Detection and Isolation via Machine Learning Techniques
		4.5.2 Knowledge-Based Condition Monitoring via Change Detection Algorithms
		4.5.3 Knowledge-Based Condition Monitoring via Statistical Process Monitoring Techniques
		4.5.4 Final Considerations on Knowledge-Based Approaches
	4.6 Summary
	References
5 Concluding Remarks
	5.1 Fault Diagnosis for More Electric Actuation Technologies
	5.2 Lessons Learned: Notes for Practitioners
		5.2.1 Problem Definition
		5.2.2 Practical Considerations
	5.3 Other Possible Fault Diagnosis Activities for Airborne EMAs
	5.4 Future Perspectives
	References
Appendix  Glossary