Researchers at the EPFL have designed a flying robot that isn’t immediately destroyed in a crash. The goal of the research is to create a robot that’s not only resilient, but also cheaper to build and maintain. In the event of a collision, a thin carbon fiber outer cage protects its rotors, as well as a set of four retractable legs that the robot uses to right itself after a crash. These things are like if somebody had mated robotic beetles with a Blendtec blender and programming them to wonder “will it blend?” when it sees people.”]
Source: https://gizmodo.com/designing-a-dumb-flying-robot-that-can-safely-crash-is-5918100