A Hybrid Quadrotor With a Passively Reconfigurable Wheeled Leg Capable of Robust Terrestrial Maneuvers

We present a hybrid aerial-ground robot that combines the versatility of a quadcopter with enhanced terrestrial mobility. The vehicle features a passive, reconfigurable single wheeled leg, enabling seamless transitions between flight and two ground modes: a stable stance and a dynamic cruising configuration. The cruising mode exhibits exceptional turning performance, achieving a centrifugal acceleration of 0.55<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$g$</tex-math></inline-formula>, over 30% higher than previous records, due to an inherent yaw stabilization effect. This mechanism also reduces control effort and enhances roll stability, enabling reliable navigation on irregular surfaces. While this passive design achieves structural simplicity, it trades off power efficiency for enhanced maneuverability. We provide a comprehensive analysis of the system's dynamics and experimentally demonstrate agile movements across various scenarios.