High-Fidelity Model of Electro-Hydraulic Actuators for Primary Flight Control Systems

Abstract

Hydraulic actuators are the de facto standard for primary flight control systems, since they provide low jamming probability and intrinsic damping capabilities. Electro-Hydraulic Actuators theoretically provide a number of advantages over the traditional hydraulic systems, such as the decrease in the overall power consumption, easier installation and reduced weight of the flight control system, but are so far mostly used as back-up solutions in civil applications. Flight control actuators can face an extremely wide range of operational scenarios depending on the aircraft route, weather condition, pilot behavior and components health. The use of high-fidelity models is instrumental in the design of both actuators and control laws and can enhance the definition of a Prognostics and Health Monitoring system, given its capability to simulate a huge number of possible in-flight situations. In this paper, we provide the mathematical definition of a novel high-fidelity model for primary flight control system, discuss its implementation and results in nominal and off-nominal conditions.