Meeting Abstract
126.3 Tuesday, Jan. 7 14:00 What fruit-flies care about – A hierarchy of rotational control in free flight BEATUS, T.*; RISTROPH, L.G.; IAMS, S.M.; HENCEY, B.M.; GUCKENHEIMER, J.M.; COHEN, I.; Cornell University; New York University; Cornell University; Cornell University; Cornell University; Cornell University tb343@cornell.edu
Flying insects manage to maintain aerodynamic stability despite the inherent instability of flapping flight and the mechanical perturbations they are constantly subject to. How flies quickly correct for flight disturbances within only a few wing beats remains an outstanding problem in insect flight research, especially since each wing beat is controlled by a single neural pulse. Our experiment implements reproducible, controlled mechanical perturbations to free-flying fruit-flies and simultaneously measures their full wing and body kinematics. We glue a small magnet to the back of each fly and apply a short magnetic pulse that rotates the insect in mid-air along its body roll angle, which is the most unstable degree-of-freedom in flapping flight. Here we show that fruit-flies manage to fully recover from roll perturbation as large as 100o within ~9 wing beats, comparable to their visual response time. To generate corrective torques, the flies apply a stroke-amplitude asymmetry that is well-described by a linear PI controller, the same controller type used by engineers for attitude control of airplanes and spacecrafts. Finally, we provide the first experimental evidence for a hierarchy among the rotational degrees-of-freedom flies care about. Roll is the most important, next is pitch and then yaw, suggesting that the overall flight controller is cascaded. These results pose roll correction in fruit flies as a model system for extremely fast bio-locomotion control.
