An agile flapping-wing robot designed to better illuminate the full range of movement associated with free flight reveals new insights into how flying insects like the fruit fly perform rapid banked turns, often used for escaping predators. According to the report, the robot's unique bioinspired flight capabilities provide an effective new analog for studying a range of demanding insect flight tasks, including takeoff, landing, quick turns and skillful chasing. Flying robots can be used to better understand the nimble aerial movements of their living counterparts. Insects are among the most agile flying creatures on Earth, capable of rapid twists and turns while catching prey or evading an angry, swatting hand. Research into the aerodynamics that makes these maneuvers possible typically involves in vivo observations of flight using high-speed cameras, theoretical modeling or using scaled robots tethered to external power supplies. However, according to the authors, these methods are limited or incapable of modeling the full range of movement associated with free flight. Mat?j Karásek and colleagues developed an autonomous, free-flying insect-inspired robot with four flapping wings. Like in flies, the flapping flyer is tailless; thus its flight position and orientation are controlled only through precise adjustments in wing motion. It could be used to study flight dynamics and control in a wide range of flying animals. To demonstrate its potential for animal flight research, Karásek et al. programmed the robot to mimic the evasive rapid banked turns observed in fruit flies. They found that, despite being more than 55 times larger, the robot could accurately replicate the maneuver dynamics of the fruit fly. The results reveal the use of a passive approach to controlling the banked turn maneuver and minimizing sideslip, not an active one - and specifically an approach called translation-induced yaw torque coupling. In a related Perspective, Franck Ruffier discusses the implications of the well-designed bio-inspired robotic flapper, including the significance of its revelation that elements of sophisticated flight tasks are passively controlled.
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Journal
Science