Design of Wing Root Rotation Mechanism for Dragonfly-Inspired Micro Air Vehicle

Jae Jang,Gi-Hun Yang

doi:10.3390/app8101868

Abstract

This paper proposes a wing root control mechanism inspired by the drag-based system of a dragonfly. The previous mechanisms for generating wing rotations have high controllability of the angle of attack, but the structures are either too complex or too simple, and the control of the angle of attack is insufficient. In order to overcome these disadvantages, a wing root control mechanism was designed to improve the control of the angle of attack by controlling the mean angle of attack in a passive rotation mechanism implemented in a simple structure. Links between the proposed mechanism and a spatial four-bar link-based flapping mechanism were optimized for the design, and a prototype was produced by a 3D printer. The kinematics and aerodynamics were measured using the prototype, a high-speed camera, and an F/T sensor. In the measured kinematics, the flapping amplitude was found to be similar to the design value, and the mean angle of attack increased by approximately 30° at a wing root angle of 0°. In the aerodynamic analysis, the drag-based system implemented using the wing root control mechanism reduced the amplitude of the force in the horizontal direction to approximately 0.15 N and 0.1 N in the downstroke and upstroke, respectively, compared with the lift-based system. In addition, at an inclined stroke angle, the force in the horizontal direction increased greatly when the wing root angle was 0° at the inclined stroke angle, while the force in the vertical direction increased greatly at a wing root angle of 30°. This means that the flight mode can be controlled by controlling the wing root angle. As a result, it is shown that the wing root control mechanism can be applied to the MAV (micro air vehicle) to stabilize hovering better than the MAV using a lift-based system and can control the flight mode without changing the posture.

Highlights

Small birds and insects are good objects to mimic for developing a micro air vehicle (MAV)for stable flight at low Reynolds fluid [1,2,3,4,5,6,7]
The purpose of this study is to develop a passive rotation that mimics the mean angle of attack changes wing rootarotation withwing respect to themechanism horizontal direction of the
We developed mean angle of attack changes by wing root rotation with respect to the horizontal direction of the wing when thethe wing has has the same angleangle of attack at each up-down stroke.stroke

Summary

Introduction

Small birds and insects are good objects to mimic for developing a micro air vehicle (MAV)for stable flight at low Reynolds fluid [1,2,3,4,5,6,7]. In order to achieve this high maneuverability, the dragonfly uses characteristics such as the phase difference between the forewing and hind wing [8,10,11,12], independent control of each wing [13], and a drag-based system in hovering flight [14,15]. Among these characteristics, we focus on the drag-based system. Dragonflies use a drag-based system in which they stroke

Objectives

Methods

Findings

Conclusion