Quadrotor are expected to use in disaster investigation or infrastructure inspection. There are complex structure and narrow spaces in these field. In flight on such an environment, there is a high risk of crash due to contact with an obstacle. Therefore, this paper proposes a quadrotor with a rotating spherical shell. The shell can be rotated freely independently of the quadrotor, so it can parry the impact of collision. We designed the prototype, and it was examined experimentally.
