Improving Safety and Reducing Size in Multicopters by Adjusting Propeller Height and Its Applications to Remote Sensing

Abstract

In this study, we proposed a drone structure that is safer than the conventional propeller guard structure and that can reduce drone size as compared with conventional drones. This is achieved by making the rotating blade regions overlap by setting a height difference on adjacent rotor blades. We showed that drones with the proposed structure that have four, six, or eight rotors (quadcopters, hexacopters, or octocopters) can achieve size reductions of about 27%, 46%, or 54%, respectively, as compared with drones with a conventional structure. To evaluate the proposed method, an actual drone was manufactured, and its propulsion capability and control performance were evaluated in an indoor experiment. The results confirm that the performance of the experimental drone was almost equivalent to that of a conventional drone. In addition, we constructed several of the newly proposed drones, built their coordinated flight control units, and conducted demonstration experiments in an outdoor environment, suggesting a framework for high-precision measurement using drones. The results show that the proposed drone structure can reduce the size of the airframe while also reducing the risks associated with the rotor blades. These new drones could be used to eliminate bottlenecks in breeding measurement using drones