Department of Physics, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2010 Apr 9;104(14):148101. doi: 10.1103/PhysRevLett.104.148101. Epub 2010 Apr 5.
Flying insects execute aerial maneuvers through subtle manipulations of their wing motions. Here, we measure the free-flight kinematics of fruit flies and determine how they modulate their wing pitching to induce sharp turns. By analyzing the torques these insects exert to pitch their wings, we infer that the wing hinge acts as a torsional spring that passively resists the wing's tendency to flip in response to aerodynamic and inertial forces. To turn, the insects asymmetrically change the spring rest angles to generate asymmetric rowing motions of their wings. Thus, insects can generate these maneuvers using only a slight active actuation that biases their wing motion.
飞行昆虫通过微妙地操纵翅膀运动来执行空中机动。在这里，我们测量了果蝇的自由飞行运动学，并确定了它们如何调节翅膀俯仰来诱导急转弯。通过分析这些昆虫施加到翅膀上的扭矩，我们推断出翼铰链充当扭转弹簧，它被动地抵抗由于空气动力和惯性力而导致的翅膀翻转的趋势。为了转弯，昆虫会不对称地改变弹簧的静止角度，从而产生翅膀的不对称划动运动。因此，昆虫只需稍微主动地偏置其翅膀运动，就可以产生这些机动动作。
