Meeting Abstract

84.4  Monday, Jan. 6 11:15  A robotic model of inertial flight maneuvering in the hawkmoth ROMBOKAS, E*; SCHEUER, L; DYHR, JP; DANIEL, TL; University of Washington eric.rombokas@gmail.com

Recent studies have shown that the hawkmoth Manduca sexta displays a marked abdominal flexion reflex in response to both visual and mechanical cues associated with pitch perturbations. The extent to which such airframe deformation can be used as a control concept for either animals or synthetic systems remains an open problem. To establish control policies for such systems, we developed a robotic “bi-rotor” that has an actuated mass representing an insect abdomen. Importantly, bi-rotors are inherently pitch unstable without active stabilization mechanisms. As such this platform allows us to test hypotheses about control principles that involve conservation of angular momentum along with inertial redirection of thrust forces. The bi-rotor differs from the popular “quad-rotor” in that it uses only two rotors, approximating the two sets of wings in the insect, and stabilizes pitch by movement of an abdomen-like structure hanging beneath and containing the heavy battery. This platform, suggested by the Hawkmoth studies, exhibits a subset of the dynamics found in the insect and allows us to establish the minimum necessary criteria for control. In particular we show how abdominal flexion using only proportional gain is insufficient for pitch stabilization. The addition of appropriately weighted active damping provides some stability, but does not provide the dexterous agility found in the insect. The emergent dynamics of the system, including flips and rapid spins, demonstrate that biologically-inspired active airframe deformation can provide control authority for unstable bi-rotors.