Flight Control System of a Tiltwing UAV

This paper describes the development and validation process of the flight control system of a tiltwing UAV with focus on the transition control. Due to the capability to tilt its main wing the special aircraft type combines the advantages of a fixed-wing aircraft concerning flight performance and energy consumption with the VTOL capabilities of a rotary-wing configuration, which implies a high flexibility for multi role operations. Thus the hybrid aircraft concept closes a gap between common configurations. A particular challenge for the flight control system is to handle the unsteady states in transition phase between horizontal and vertical flight and to ensure full control of the aircraft at any time. The presented flight control system is designed for an aircraft with a wingspan of 6.56 ft / 2 m and a maximum gross weight of 24.25 lbs / 11 kg and was tested successfully within a software simulation environment as well as partially in a free flight test campaign.