Design and Control Evaluation of a Novel Subscale Quad-Tiltrotor

摘要

Vertical takeoff and landing (VTOL) aircraft have attracted significant attention in both the military and civilian market due to the flexibility of vertical flight and the efficiency of wing-borne flight. Many of these aircraft also include tiltrotor or tiltwing mechanisms to achieve "conversion" or "transition" from horizontal to vertical flight and vice versa. The complex aerodynamics, flight dynamics, and control of transition are among the most difficult aspects of the design of tiltwing and tiltrotor VTOL aircraft. In this paper, we describe the methodology used to develop a novel subscale aircraft that was designed and built as an example to investigate controls development and flight testing of eVTOL aircraft that have difficult transition aeromechanics and flight performance. The aircraft is a modular tiltrotor that uses four rotors for vertical lift and tilts the two rear rotors for forward thrust. The design leverages off-the-shelf components and well-understood quadcopter controllers to move the aircraft from concept to full functionality as quickly and reliably as possible. The methodology for controls development is based on managing complexity and reducing risk through incremental testing and maintaining high performance margins. This paper presents the unique elements of the aircraft design along with the process used to develop and test the control system.