Design and Evaluation of Fault-Tolerant Electro-Mechanical Actuators for Flight Controls of Unmanned Aerial Vehicles

Electro-mechanical actuators (EMAs) are a primary actuation technology for unmannedaerial vehicles (UAVs). Intensive research has been conducted for designing and evaluating fault-tolerant EMAs for flight controls of UAVs to ensure their compliance with new airworthinessrequirements for safe operation over civilian zones. The state-of-the-art research involves severalfault-tolerant architectures for EMAs based on parallel electric motors or a single motor with internalfault-tolerant features. In this study, a fault-tolerant architecture is introduced, comprised of two serialelectric motors driven by two isolated controllers and a health monitoring system. The proceduresof developing various fault-tolerant features are discussed with a deep focus on designing healthmonitoring functions and evaluating their influence on the overall actuator stability and availability.This work has been conducted and evaluated based on operational data for ALAADy: a heavygyrocopter-type UAV at DLR (German Aerospace Center)