A Study on Glide Characteristics of a Small Flapping Robot

抄録

In this paper, we analyze the flight characteristics, such as glide ratio and attitude stability, of a butterfly-style flapping robot with a simple body design and unique wings. Although flapping flight allows vertical takeoff, hovering, sharp turn, and efficient migration, which are not possible for conventional fixed-wing aircraft, gliding is also important to conserve energy, even for a small flapping insect. Here, we aim to develop an insect-scale flapping robot that can transition between flapping and gliding flights and experimentally analyze the flight characteristics of a tailless flyer with low aspect ratio and elastic membrane wings. The experimental analysis using the fabricated flapping robot with a mass of 459mg, a wingspan of 122mm, and an aspect ratio of 3.0 revealed that the robot had a glide ratio of 3.9 for an angle of attack of 17deg (pitch angle: 2.2deg) and a flight velocity of 1.9m/s. Moreover, the body design with the center of gravity located under the estimated center of lift created longitudinal stability and recovered the pitch attitude from initial pitch angles of ±30deg during a descent of 12 body lengths. On the other hand, this body design and the dihedral angle of 10deg created lateral stability and recovered the roll attitude from initial roll angles of 30deg and 60deg during a descent of 11 body lengths.