Transition Flight Dynamics of a Dual Tilt-Wing UAV

A hybrid unmanned autonomous vehicle (UAV) combines the high-speed cruise capability of a fixed-wing airplane, with the hovering flight, vertical take-off and landing capabilities of a helicopter. The change between both flight modes refers to as a transition flight process. This paper presents the flight dynamics during the transition stage of a hybrid UAV of Dual Tilt-Wing type. A non-linear mathematical model is developed that includes the UAV complete dynamics, which presents significant changes in aerodynamic characteristics, especially during the transition flight. These changes are analyzed and characterized by flight tests and CFD simulations. The adaptation to the variation of aerodynamic characteristics caused by tilt angle changes of transition system is verified, so a PD controller for altitude is implemented.