We are just back from the Maker Faire Berlin where we have met lot of interesting people and shown the loco positioning system. We have calculated that Crazyflie 2.0 has flown for more than 91% of the faire thanks to the autonomous flight with Loco Positioning System.
Our neighbor at the Maker Faire was Gerhard Fließ from Deskbreeze and he was presenting a mini desktop wind-tunnel:
This was a great opportunity for us to test the Crazyflie in a wind-tunel. The result is really impressive slow motion videos:
The wind-tunnel is mainly designed for education. The wind goes at 1 m/s which is apparently too slow for aerodynamic study but nevertheless we can see some interesting effects. Then the propeller pulls the air, we can see the lines getting tighter just before the propeller, this is a sign of higher speed flow and lower pressure. The difference of pressure between the bottom and the top of the propeller is what makes the Crazyflie fly. When the Crazyflie pushes the airflow, simulating a descent, we can see an oscillation of the air flow. This is most likely what can cause instability when descending fast.
We will post more about the Maker Faire Berlin and our autonomous flight demo in the following weeks so stay tuned. Thanks to all we have met, it is awesome to meet and talk about the Crazyflie in person. A mostly great thanks to Fredg (derf on the forum ;), that was there to help us during the whole week end.
Cool video! It amazes me how the things get more understandable when shown in the wind-tunnel. Good luck for your project! Gabriele