A passive dynamic approach for flapping-wing micro-aerial vehicle control

This article outlines a new control approach for flapping-wing micro-aerial vehicles (MAVs), in-spired both by biological systems and by the need for lightweight actuation and control solutions. In our approach, the aerodynamic forces required for agile motions are achieved indirectly, by modifying passive impedance properties that couple motion of the power stroke to the angle of attack (AoA) of the wing. This strategy is theoretically appealing because it can ex-ploit an invariant, cyclical power stroke, for efficiency, and because an impedance-adjusting strategy should also require lower bandwidth, weight, and power than direct, intra-wingbeat control of AoA. We examine the theoretical range of control torques and forces that can be achieved using this method and conclude that it is a plausible method of control. Our results demon-strate the potential of a passive dynamic design and control approach in reducing mechanical complexity, weight and power consumption of an MAV while achiev-ing the aerodynamic forces required for the types of high-fidelity maneuvers that drive current interest in au-tonomous, flapping-wing robotics. NOMENCLATURE c(r) Chord length of wing, at radius r cm(r) Mean chord position, at radius r COP Center of pressure on wing during flapping c̄w Normalized mean chord lengt