To realize the turning motion of the micro aerial vehicle, we developed a mechanism that reproduces the lead-lag motion of a butterfly. The effectiveness of this mechanism was verified through flight experiments and numerical simulations of a glider equipped with this mechanism. Butterflies turn using the lead-lag motion, which involves moving the left and right wings back and forth. In this study, we developed a mechanism to achieve this lead-lag motion using a shape memory alloy actuator based on our butterfly-type flapping robot. The mechanism was implemented in a butterfly-shaped glider, and flight experiments and numerical simulation analysis with computational fluid dynamics were conducted. The results of 3D motion analysis using multiple high-speed cameras revealed that the developed lead-lag mechanism allows the left and right wings to have different lead-lag angles during glide flight. This mechanism was confirmed to enable the right turn by increasing the lead-lag angle of the left wing as well as the left turn by increasing the lead-lag angle of the right wing. Numerical simulation analysis demonstrated that changes in the left and right lead-lag angles generated yawing and rolling moments, respectively, and that this produced turning motion with a change in the yaw angle.

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