A prototype of an autonomous battery-exchange platform for drones, made in LEGO. Website: http://valhalla.utopi.dk/ The video is also uploaded to this page: http://valhalla.utopi.dk/product.html and can be watched there, if the video is blocked in your country.
![Autonomous battery-exchange platform for drones (Lego Mindstorms)](https://cdn-ak-scissors.b.st-hatena.com/image/square/345ffb7fc5c404b3aa4377f755b3387ae856a730/height=288;version=1;width=512/https%3A%2F%2Fi.ytimg.com%2Fvi%2F5iQnnXwnk2s%2Fhqdefault.jpg)