In my lab, we build autonomous aerial robots like the one you see flying here. Unlike the commercially available drones that you can buy today, this robot doesn't have any GPS on board. So without GPS, it's hard for robots like this to determine their position. This robot uses onboard sensors, cameras and laser scanners, to scan the environment. It detects features from the environment, and it determines where it is relative to those features, using a method of triangulation. And then it can assemble all these features into a map, like you see behind me. And this map then allows the robot to understand where the obstacles are and navigate in a collision-free manner.