熊蜂机动飞行动稳定性

针对目前飞行昆虫的动力学特性分析仅限于定常飞行,采用分叉分析方法研究了熊蜂的机动稳定性.分别以俯仰角速度和偏航角速度作为参变量,计算急停过程和急旋变向过程中各平衡点的稳定性并判断其稳定范围,分析熊蜂在不同前飞速度时的全局稳定性.结果表明:熊蜂在前飞速度为0时进行急旋变向是全局稳定的,偏航角速度为14.23rad/s<| r |<23.8rad/s具有唯一的稳定焦点,在前飞速度为2.5m/s和4.5m/s时进行急旋变向是不稳定的,这解释了飞行昆虫为何在急旋变向前降低飞行速度.熊蜂在不同速度处的急停都不是全局稳定的,会进入不稳定的大幅振荡,但发散之前具有一个约为30个扑动周期的过渡间隙,因此熊蜂由足够的调整时间. 

Dynamic stability for maneuver flight of bumblebee

In allusion to the fact that current flight dynamic analysis of insect is limited to steady flight,the maneuver flight stability of bumblebee is analyzed with bifurcation analysis.The coupling stability of saccade and turning in maneuver flight is studied by analyzing the stability and stability field of different equilibrium point.Then get the global stability of saccade and turning at different forward speed.As the results have put it,turning at hovering is global stability and existing only and one stable focus when 14.23rad/s<| r |<23.8rad/s;turning at flying velocity are 2.5m/s and 4.5m/s is unstable,which explains why the insects are to reduce speed before turning;the bumblebee saccade at different forward speed are unstable and enter sharply unstable oscillation.However,there exists a transition time of 30 flapping period,which is enough for bumblebee to adjust.