Drone rotor failures can cause serious accidents. “When a rotor fails, the drone starts rotating around its own axis like a ballerina,” explains robotics researcher Davide Scaramuzza in a statement released by the University of Zurich. In the absence of a GPS signal, or if the GPS signal is weak, this rotation prevents the drone from being able to accurately determine its position, causing it to crash.

Recently, however, researchers at the University of Zurich developed a solution that involves equipping the propellers of a quadrocopter, a drone with four rotors, with two types of cameras. They installed not only standard cameras that take several shots per second, but also special cameras that are activated only when the ambient light changes.

New algorithms programmed by the researchers combine the information from both sensors to allow the drone to continuously track its position. Test flights have proven that their flying robot can orient itself even in dim lighting conditions and can thus still be controlled by the on-board computer with pinpoint accuracy – even in the event of a rotor failure.