Development and Design Optimization of 2Y Hexarotor with Robustness against Rotor Failure

This paper presents a novel hexarotor unmanned aerial vehicle (UAV) with robustness against an arbitrary rotor-failure, called full robustness, and a design method to maximize its manipulability while ensuring the full robustness. First, the dynamical model of a hexarotor UAV and the novel structure with 2Y shape and twisted angles are presented. A hexarotor with this structure is named as 2Y hexarotor. The 2Y hexarotor has higher flight efficiency than other existing hexarotor structures with full robustness. Second, the full robustness of the 2Y hexarotor is proved, and a quantitative measure to evaluate the full robustness is introduced. Then, the quantitative measure for the full robustness is used to calculate the optimal twisted angles. Finally, the dynamic manipulability measure (DMM) is introduced to evaluate the maneuverability. A design method is defined as the maximization of the DMM under constraints regarding the quantitative measure for the full robustness and the condition to avoid overlapping rotors. The design method is applied to the 2Y hexarotor with the optimal twisted angles.