Recently, researching about security in autonomous flight, robotics context, I found this 2013 TED Talk, made by a teacher, researcher and inventor - Raffaello D'Andrea - which puts into practice and explains flight algorithms, and the result is what can, and should, see in the video. I mean, it's a must see!
Out of curiosity, what brought me to this TED Talk was the demonstration made in a 4 multirotor propellers , in which 2 are deliberately destroyed to prove the efficiency of an anti-disaster algorithm. To express the importance of this statement: within the aeromodeller community, a similar system to the shown has, in general, 0% tolerance to these kind of failures.
The last curiosity is that Raffaello D'Andrea is co-founder of Kiva Systems, a company acquired by Amazon in 2012... go figure!