Design and Realization of New Conceptual Collectible Rotor for Compound Aircraft

A compound aircraft with a collectible rotor has the ability of vertical take-off and landing (VTOL), high-speed flight and long-range cruising. Compared to systems in other compound aircraft, the collectible rotor can work as a conventional rotor in helicopter mode and can be gathered into a disk in the center in fixed-wing mode, thereby relieving the rotor's limitations pertaining to forward flight performance. The collectible rotor is a key component in the design and realization of a compound aircraft. Based on a 35-kg-level prototype, in this study, the principle of a folding rotor is proposed, a dynamic model of the rotor is established considering the complex nonlinear compound motion of rotation and folding, and the aerodynamic and dynamic characteristics are analyzed considering the coupling of different speeds of the rotor and folding strategies for the folding process. According to the above research, a complete rotor system, including an unconventional rotor structure, closed-loop real-time control system, and high-torque driving system, is designed. A demonstration model was constructed to verify the feasibility of the folding rotor. Finally, through an on-board test, the folding rotor system was verified in a simulated real flight state. This paper provides a theoretical basis for folding rotor design and proposes a set of design methods and research concepts.