An Aerial Robot Achieving Bimodal Flight and Independent Attitude Control through Passive Morphing

Enhancing the adaptability and versatility of unmanned micro aerial vehicles (MAVs) is crucial for expanding their application range. In this article, a bimodal reconfigurable robot capable of operating in both regular quadcopter flight mode and a unique revolving flight mode is presented, which allows independent control of the vehicle's position and roll-pitch attitude. This design incorporates passive revolute joints that enable seamless mid-air transitions between the two modes, facilitated by centrifugal forces, without the need for additional actuators. In the regular mode, the robot operates with four vertical propellers, similar to conventional designs. In the revolving mode, the configuration shifts to two horizontal and two vertical propellers, achieving five degrees of freedom control with four actuators. This underactuated flight capability is made possible by exploiting the robot's fast revolving motion and the resulting cycle-averaged forces and torques. Experimental validations confirm the feasibility and enhance the maneuverability of this design. The revolving flight mode provides significant advantages in applications such as mapping and confined space navigation. © 2024 The Author(s). Advanced Intelligent Systems published by Wiley-VCH GmbH.