Design and Implementation of a Dual-Mode UAV Combining Single-Rotor with Coaxial-Rotor for Indoor Applications

A novel dual-mode unmanned aerial vehicle (UAV) is designed in this paper. The high aerodynamic efficiency of a single-rotor system is integrated with the strong payload capacity and stability provided by a coaxial twin-rotor configuration. A quick-release propulsion system is featured in the proposed UAV, and its design is specifically optimized for indoor reconnaissance, inspection, and surveillance applications. In comparison with conventional small UAV designs—such as tilt-rotor and quadrotor platforms—key limitations in control stability, payload capability, flight efficiency, indoor safety, and miniaturization are addressed by this system. A compact form factor and an empty weight of only 225 grams are exhibited by the dual-mode UAV, and a maximum thrust-to-weight ratio of 4 is achieved. Seamless switching between flight modes is enabled by its innovative structural design and control logic, ensuring both agility and robustness in confined environments. Superior performance in both flight efficiency and payload capacity is confirmed through experimental evaluations, and a promising new solution for indoor UAV applications is offered.