Assessment of power consumption of helicopter flight control systems without swashplate

Abstract

Nowadays helicopter ight control in the most common congurations is realized by collective and cyclic variation of the angle of attack of each rotor blade. The collective blade control pitches the rotor blades to equal angles of attack around their longitudinal axis, changing the rotor thrust at constant rotor speed. Yaw and roll control is realized via cyclic blade motion by changing the angle of attack of every rotor blade locally and periodically during one revolution. Although y-by-wire and y-by-light technologies slowly have found entry into helicopter ight control systems in the last years, complex mechanical systems are state-of-the-art to transfer all required control signals and forces from the fuselage into the rotating main rotor system. By Individual Blade Control (IBC) in higher harmonic modes and with additional actuators in the rotating system, fuselage vibrationsand radiated noise can be reduced and as well other IBC effects. This technology is subject of intensive research work [1]. The intention of the research project INHUS (iInnovative Steuerungskonzepte f¤ ur Hubschrauberi) is the identication of a combined actuation system for primary ight control and IBC, which corresponds to the essential requirements of light weight, low control power consumption and high reliability. Therefore, a wide variety of technologies will be evaluated in terms of aforementioned requirements, uneffected by known ight control implementations in helicopters. The content of this paper is the comparison of the required power of different hydraulic and electric actuation systems, designed on the basis of specication data of a 20 tonsnhelicopter during several steady ight conditions.