Untethered Flight of an At-Scale Dual-Motor Hummingbird Robot with Bio-Inspired Decoupled Wings

In this letter, we present the untethered flight of an at-scale tailless hummingbird robot with independently controlled wings. It represents the first untethered stable flight of a two actuator powered bio-inspired Flapping Wing Micro Air Vehicle (FWMAV) in both indoor and outdoor environment. The untethered flight of such FWMAVs is a challenging task due to stringent payload limitation from severe underactuation and power efficiency challenge caused by motor reciprocating motion. In this work, we present the detailed modeling, optimization, and system integration of onboard power, actuation, sensing, and flight control to address these unique challenges of such FWMAV during untethered flight. We performed untethered flight experiments in both indoor and outdoor environment and demonstrate sustained stable flight of the robot.