Inner-Loop Feedback for Deadband Compensation in Electromechanical Flight Surface Actuation Systems

This manuscript pertains to the application of an inner-loop control strategy to electro-mechanical flight surface actuation systems. Modular Electro-Mechanical Actuators (EMA) are increasingly used in-lieu of centralized hydraulics for the control of flight surfaces in the aerospace sector. The presence of what is termed as a dead zone in these actuators significantly affects the maneuverability, stability, and the flight profiles of aircrafts that use this actuation concept. The hypothesis of our research is that flight surface actuation systems may be desensitized to the effects of dead zone by using a control strategy with multiple inner-loops. The proposed strategy involves: high-gain inner-loop velocity control of the driving motor; and inner-loop compensation for the differential velocity between the motor versus the aileron. Our results indicate that this strategy is very effective and that it can considerably improve the system’s performance. The above hypothesis is confirmed by theoretical and simulated analysis using the model of an EMA flight surface actuator.Copyright © 2005 by ASME