Control and guidance for a tail-sitter unmanned air vehicle

This paper details the control and guidance architecture for the T-Wing tail-sitter unmanned air vehicle, (UAV). The vehicle uses a mixture of classical and LQR controllers for its numerous low-level and guidance control loops. Different controllers are used for the vertical, horizontal and transition flight modes, glued together with supervisory mode-switching logic. This allows the vehicle to achieve autonomous waypoint navigation throughout its flight-envelope. The control design for the T-Wing is complicated by the large differences in vehicle dynamics between vertical and horizontal flight; the difficulty of accurately predicting the low-speed vehicle aerodynamics; and the basic instability of the vertical flight mode. This paper considers the control design problem for the T-Wing in light of these factors. In particular it focuses on the integration of all the different types and levels of controllers in a full flight-vehicle control system.