Overview

Electro-Mechanical Actuators (EMA) are presently used in numerous aerospace applications, from robotic applications to thrust vector control of rocket engines, where they accomplish a range of rotational and translational functions. There is an increasing tendency to move to all-electric aircraft and spacecraft designs (i.e. no hydraulic systems), so an even wider use is likely in the future.

The application that this research focuses on is aircraft flight control systems. Such systems are critical for flight safety and must not only provide level of reliability, but also a high level of fault tolerance. Even when in a degraded state, a flight control EMA must be able to operate in such a way as to allow achievement of the major mission objectives and a safe conclusion of the flight. Along with the more traditional methods of improving EMA designs, incorporating comprehensive prognostic and health management (PHM) systems into them would contribute significantly to their reliability and fault tolerance.

In order to make such PHM systems feasible, this project concentrates on the following research goals:

• Detect and classify incipient fault conditions
• Reliably estimate the Remaining Useful Life (RUL), for both nominal and degraded operating regimes
• Generate real-time actions or recommendations for extention of RUL with changes in the operating modes or environment
• At any point during its lifetime, provide an acurate picture of EMA component health to maintenance crews, enabling on-demand, selective servicing

In this effort, both model-based and data-driven reasoning algorithms are used for real-time performance monitoring. If any discrepancies are detected, the reasoning algorithms would determine if the discrepancy is due to a fault condition and if so, how severe the condition is and how is it likely to propagate in the future.