在仿生学习网络的大框架下，我们坚持开发飞行相关产品的历史已超过 15 年。在此期间，我们研究了大量飞行动物及其自然原理，获得了很多技术成果，也在不断从生物模型中学习。自主的集体性行为是我们曾面临的一大挑战。BionicBee 是我们开发的第一款能够大规模、完全自主集体飞行的产品。
BionicBee 重约 34 克，长 22 厘米，翼展 24 厘米，目前是仿生学习网络中最小巧的飞行器。在研发过程中，开发人员首次采用了衍生式设计方法：只需输入少量参数，软件就会基于定义的结构设计，设计出最佳结构，从而以最少的材料实现尽可能稳定的构造。这种一致的轻量化设计，其对于实现出色的机动性和飞行时间至关重要。
这种“蜜蜂”的内部构造非常紧凑，集成有翅膀扇动机构、通讯技术组件和控制组件，用于扇动翅膀和调节翅膀的几何形状。我们采用了可能节省空间的构造方式，其中安装有一个无刷电机、三个伺服电机、电池、减速机和各种电路板。电机与机械装置可实现智能协同作用，从而精确地调节翅膀扇动频率，完成不同动作。
这种人造蜜蜂的飞行频率为 15 至 20 赫兹。飞行时，它的翅膀会 180 度来回拍打。精确且超轻的受控机械结构控制内部的无刷电机，无间隙地驱动振翅机构。电机转速越高，振翅频率和升力就越高。蜜蜂的翅膀根部安装有三个伺服电机，能够有针对性地改变翅膀的几何形状，从而提高特定翅膀位置的效率，然后有针对性地调整所产生的升力。
如果蜜蜂要往前飞，就会适当调整翅膀的几何形状，使翅膀后部位置的升力大于前部位置。在这种情况下，蜜蜂的身体会向前倾斜（俯仰），并开始向前飞行。如果将几何形状调整为右边翅膀产生的升力比左边翅膀大，那么蜜蜂就会绕着纵轴向左滚动（翻滚），并从侧面飞走。此外，还能将几何形状调整为使一个翅膀在前面产生更大的升力，而另一个翅膀在后面产生更大的升力。这样就会使蜜蜂围绕垂直轴转动（偏航）。
The autonomous behaviour of the ten bees is made possible by an indoor localisation system with ultra-wideband technology (UWB). Eight UWB anchors are installed on two levels in the space. This means that the runtime can be accurately measured and the bees can position themselves in the space. The UWB anchors send signals to the individual bees, which independently measure the distances to the transmitters and can calculate their own position in the space using the time stamps.
To fly in a swarm, the bees follow the paths specified by a central computer. High spatial and temporal accuracy is required for safe and collision-free flight in close formation. Possible mutual interplay caused by air turbulence ("downwash") must also be taken into account when planning the route.
As each bee is built by hand, even the smallest manufacturing differences can influence flight behaviour. That's why the bees also have an automatic calibration function, so that after a short test flight, each bee determines its own optimised controller parameters. This is how the intelligent algorithm can work out the hardware differences between the individual bees. And that, in turn, allows the entire swarm to be controlled externally as if all the bees were identical.
When developing the BionicBee, the developers took advantage of the numerous insights they gained during previous projects. It is the next in a series of bionic flying objects that have been created as part of our Bionic Learning Network. For over 15 years, we have been developing research platforms using general technical principles that are based on nature. Click on the links below to have a quick look at them.