Observer-based Angle of Attack Estimation for Tilt-Wing eVTOL Aircraft

Research and development have been very active in electric vertical takeoff and landing (eVTOL) aircraft. Tilt-Wing aircraft especially receive significant attention as one of the most efficient configurations; however, they are apt to be unstable during the transition from hover to cruise. The angle of attack (AoA) is a critical parameter for aircraft motion, and with its real-time data, Tilt-Wing aircraft would achieve a more robust transition. Conventional methods of obtaining AoA require either additional sensors or an aircraft model, which is not robust to propeller slipstreams and unsuitable for Tilt-Wing aircraft. In this paper, a new AoA estimation method for Tilt-Wing aircraft is proposed. The proposed method is based on the propeller dynamics model and requires only an existing pitot tube. Wind tunnel tests verify its effectiveness.