High-Speed Compound Rotorcraft Flight Control Design And Assessment

Abstract

To support current defense initiatives such as NATO's Next Generation Rotorcraft Capability, which aims for the development and fielding of rotorcraft with higher maximum airspeed, the German Aerospace Center (DLR) has been conducting various studies regarding high-speed-capable rotorcraft configurations. Using DLR's Integrated Rotorcraft Initial Sizing environment, a high-speed compound rotorcraft was sized and designed to achieve airspeeds above 240 knots. The configuration features a main rotor, a tail rotor, a pusher propeller, a wing, and an empennage. The wings and empennage are equipped with additional aerodynamic control surfaces. This paper briefly presents the designed high-speed rotorcraft and its linear model properties. The focus of the paper is the development of an explicit model-following flight control system for the compound rotorcraft across the entire flight envelope. The corresponding feedback gains are optimized with MATLAB systune. The utilized optimization goals and their relation to ADS-33E criteria are examined. The designed flight control system is mostly predicted to achieve a Level 1 ratings.