Design of Tail-Sitter UAV and Its Tilt Transition Flight Mode Control Strategy

A tail-sitter UAV is an aircraft capable of vertical takeoff, landing, and cruising. Different design philosophies lead to various configurations requiring distinct flight mode control strategies. This paper employs the Quality Function Deployment (QFD) method to design a tail-sitter UAV with slipstream rudders and additional control features. This design makes it easy to carry mission payloads and allows for vertical takeoff and landing on platforms like naval ships. First, a QFD framework is constructed based on mission requirements to determine the aircraft configuration and parameters, and to select the control components. Next, the longitudinal dynamics model for the transition flight mode is developed and simplified. A comparative analysis of two transition flight mode control strategies with and without slipstream rudders, evaluating their controllability margins and effectiveness. This indicates that the designed tail-sitter UAV is conceptually feasible, with successful transition between flight modes. The slipstream rudder design effectively enhances the control effectiveness of the UAV during the transition flight mode.