Development and Experimental Validation of Aerial Vehicle With Passive Rotating Shell on Each Rotor

Aerial robotics is a fast-growing field of robotics and has been successfully used in various applications. Still, it faces many challenges, such as dealing with unavoidable obstacles in a cluttered environment. Recently, a flying robot with a protective shell that can rotate passively was introduced. The passive rotating mechanism is intended to reduce the impact force on the attitude of the UAV. However, such a system also has some limitations. Because the shell rotates passively, the ability to physically interact outside the shell is limited, and the onboard camera and other remote sensors are constantly obstructed. In this letter, a new idea is introduced in response to the limitations of the previous system while retaining the protective shell and maintaining some degrees of passive rotation of the shell. It is proposed to position two passive rotating hemispherical shells in each rotor to directly protect the propeller. This letter presents the concept, discusses the design and proof of concept, and validates the concept through experiments. Various experiments are conducted to demonstrate the capabilities of the proposed flying robot, resolve the problem of physical interaction and camera obstruction, and introduce new advantages.