Failsafe Innovative Electromechanical Actuator with Advanced Electric Motor Control Technique Against Single Point of Failure

Abstract

Electromechanical actuators (EMAs) begin to have a greater presence in current aeronautic designs due to the energy efficiency and reliability advantages they can provide. However, the conventional mechanical design with a single combination of a ball screw and an electric motor is subject to scenarios in which a single point of failure can render it inoperative. This paper presents a failsafe innovative EMA that gives a solution to the most typical jamming issues of aeronautical electromechanical actuators, either due to ball screw or electric motor failures. Different electric motor synchronization techniques applicable to the presented mechanical EMA design are analysed, and the benefits of the most adequate control strategy, the virtual line-shafting (VLS), are validated. Finally, the implementation of the control algorithm in a simplified virtual test bench with promising results is shown. The obtained results demonstrate that the proposed novel EMA mechanical design can enhance the failsafe capabilities of the current EMA designs based on a single ball screw and motor combination.