Meeting Abstract
Abdominal actuation during insect flight may contribute to flight control and stability via inertial redirection of flight forces. The abdomen often composes a significant portion of the body mass of an insect and may provide important insight into the possible dual sensor-actuator role of the abdomen for flight control as recently described by the insect wings of the hawkmoth (Manduca sexta). An Euler-Lagrange multibody dynamics model was developed to assess the role of the abdomen in horizontal flight for a hawkmoth morphology. The model includes aerodynamic drag of both the abdomen and the head-thorax complex and also lends itself to adjust to other insect morphologies. This model describes the relevant state variables (positions and angles as well as their derivatives) and control variables (average lift vector and abdominal flexion torque) necessary to achieve flight. The model tests the role of the abdomen by (1) increasing and (2) decreasing the torsional stiffness and torsional damping of the abdominal-thoracic joint for (a) horizontal flight, (b) hovering flight and (c) tracking an oscillating flower. Our multibody dynamics model shows that relatively little average motion of the abdomen is associated with flight control in closed loop feedback. However, because flight is inherently pitch unstable, we predict increased variation in the abdomen flexion angle as time ensues.
