Abstract
A number of researchers have attempted to develop small flap flying objects and MAV with various actuators and devices however they have not reached practical use at the present time. One of the reasons is that flying mechanism of birds and insects has not been clarified sufficiently. In this study, we evaluate dynamic behaviors of a wing observed from the butterfly's viewpoint in its flight. We conduct a flight observation experiment of Cynthia cardui performing a free flight and fixed flight and an image analysis and calculate flapping angles, lead-lag angle and feathering angles of the butterfly performing flapping flight to clarify the relation between them.
