More on Tiny Robotics

 Still hard, but advancing. 

Minuscule Sensing Suite Is a Big Step Toward Robotic Gnats Tiny flying robots need even tinier flying sensors    By Evan Ackerman   in IEEE Spectrum

Picture: An accelerometer, camera, and microprocessor make up the hardware of a sensing and autonomy system for tiny flying robots.   Picture caption:  Sawyer B.  Fuller  

In the late 1980s, Rod Brooks and Anita Flynn published a paper in The Journal of the British Interplanetary Society with the amazing title of Fast, Cheap, and Out of Control: A Robotic Invasion of the Solar System. The paper explored the idea that instead of sending one big and complicated and extremely expensive robot to explore (say) the surface of Mars, you could instead send a whole bunch of little and simple and extremely cheap robots, while still accomplishing mission goals. The abstract of the paper concludes: “We suggest that within a few years it will be possible at modest cost to invade a planet with millions of tiny robots.”

That was 1989, and we’re still nowhere near millions of tiny robots. Some things are just really hard to scale down, and building robots that are the size of bees or flies or even gnats requires advances in (among other things) sensing for autonomy as well as appropriate power systems. But progress is being made, and Sawyer Fuller, assistant professor at the University of Washington (who knows a thing or four about insect-scale flying robots), has a new article in  Science Robotics that shows how it’s possible to put together the necessary sensing hardware to enable stable, autonomous flight for flying robots smaller than a grain of rice.

For a tiny flying robot to be autonomous (or for any flying robot to be autonomous, really) it needs to be able to maintain its own stability, using sensors to keep track of where it is and make sure that it doesn’t go anywhere that it doesn’t want to go. This is especially tricky for small-scale flying robots, because they can be pushed around by air currents or turbulence that larger robots can simply ignore. But it turns out that being tiny also has some advantages: Because the drag of the air itself becomes more dominant the smaller an aircraft gets, an onboard gyroscope becomes irrelevant, and you just need an accelerometer. Tie that to an optic flow camera to track motion, along with a microcontroller to do the computation, and you have everything you need.  ... '