6 August 2022, Hong Kong, China

Flying vertebrates exhibit sophisticated wingbeat kinematics. Their specialized forelimbs allow for the wing morphing motion to couple with the flapping motion during their level flight. Previous flyable bionic platforms have successfully applied bioinspired wing morphing but cannot yet be propelled by the morphing-coupled wingbeat pattern. Inspired by this, a team of Hong Kong scientists a bioinspired flapping-wing aerial vehicle entitled RoboFalcon, which is equipped with a novel mechanism to drive the bat-style morphing wings, performs a morphing-coupled wingbeat pattern, and overall manages an appealing flight. The novel mechanism of RoboFalcon allows coupling the morphing and flapping during level flight and decoupling these when maneuvering is required, producing a bilateral asymmetric downstroke affording high rolling agility. The bat-style morphing wing is designed with a tilted mounting angle around the radius at the wrist joint to mimic the wrist supination and pronation effect of flying vertebrates’ forelimbs. Wind tunnel tests indicate that the rolling moment of the asymmetric downstroke is correlated with the flapping frequency, and the wrist mounting angle can be used for tuning the angle of attack, lift-thrust configuration, and power consumption of the equilibrium flight state.

Credit to: A Chen