蜻蜓起飞过程飞行特征实验

针对蜻蜓自由起飞过程和准自由起飞过程进行实验观测,采用两个光轴相互垂直的高速摄像机进行拍摄,通过特征点匹配和三维重构方法准确地捕捉了两种起飞过程中蜻蜓身体和翅膀的运动参数,并进行运动特征分析与对比。实验结果表明:蜻蜓在自由起飞过程中采用同步振翅,离地后逐步转换成异步振翅(约110°),最大瞬时竖直加速度可以达到20m/s2;在准自由起飞过程中采用异步振翅(相位差180°),之后相位差逐步降低,最大瞬时竖直加速度为12m/s2;此外发现同步振翅、大攻角下拍及大拍动角有利于升力的产生。 

Experiment on flight performance of dragonfly during take-off

In view of the experimental observation of the free takeoff process and the quasi free take-off process of dragonflies, two high-speed cameras were photographed with each other perpendicular to the optical axis. The motion parameters of the dragonfly body and wings during the two take-off processes were accurately captured by feature point matching and three-dimensional reconstruction, and the dynamic analysis and comparison were carried out. The experimental results showed that the dragonfly adopted synchronous vibration wing during the free take-off process and gradually transformed into asynchronous vibration wing (around 110 degrees), the maximum instantaneous vertical acceleration could reach 20m/s2; with use of asynchronous vibration wing (phase difference of 180 degrees) in the course of quasi free take-off, the phase difference gradually decreased, and the maximum instantaneous vertical acceleration was 12m/s2. In addition, synchronous flap, large angle of attack and large flapping angle were favorable for lift.