Friction Estimation for Torque Control of Electro-Mechanical Flight Surface Actuation

Kurzfassung

Electro-mechanical actuation (EMA) is pursued for primary flight control of future commercial aircraft. This technology is expected to save effort and related cost of manufacture and maintenance. Primary flight control EMAs will be typically designed to have a high gear ratio between the motor and surface. This involves significant inertia and friction torques that must be handled by the actuator controller. The friction can vary substantially, since the actuators are exposed to changing loads and a wide temperature range. This paper describes a state observer that estimates an EMA’s friction. It is assumed to include a static and a viscous share. The observer is employed for an adaptive concept of surface torque control. The described concept has been investigated by means of simulation, test rig experiments are being prepared.