QuadRotary: Design and Control of In-Flight Transition Between Quadcopter and Rotary-Wing

Traditional quadcopters excel in flight agility and maneuverability, but often face limitations in hovering efficiency and horizontal field of view. Nature-inspired rotary wings, while offering a broader perspective and enhanced hovering efficiency, are hampered by substantial angular momentum restrictions. In this study, we introduce QuadRotary, a novel vehicle that integrates the strengths of both flight characteristics through a reconfigurable design. With no additional actuators and featuring innovative designs, such as magnet-assisted hinges and self-folding wings, QuadRotary is able to achieve bidirectional in-flight transitions. Our evaluation of the prototype, control law, and transition strategies through various flight experiments demonstrates QuadRotary's capability for agile cruising and hovering, maintaining stabilized yaw rates ranging from 0 to 45 rad/s. Notably, the recorded power consumption highlights an approximately 18.4% increase in hovering efficiency with rotary-wing configuration, attributed to the presence of wings. These findings not only underscore QuadRotary's superior operational and tasking efficiency compared to existing applications but also suggest other potential implementations in the future.