When the aircraft’s center of gravity is altered, the whole aircraft will reorient and direct the thrust in the opposite direction.
What that means in terms of flight efficiency is that the center of gravity (of the battery) is shifted in one direction. For the propulsion system, they came up with a pretty ingenious approach: The propulsion system is mounted inside of a spherical cage beneath which is mounted an x-y translation stage intended to support the batteries–the heaviest component of the drone. At the bottom of the air intake, they explained, the airflow is split into four output ducts that direct the flow to the side of the sphere. This set-up allows us to control the yaw of the aircraft by adjusting the differential rotation speed of the propellers.įor the air intake, they designed a shrouded propeller system. We decided to go the way of a coaxial counter rotating rotors set-up for our propulsion. The team felt that the latter were problematic where airflow issues were concerned, so they set about trying to eliminate that problem: They also researched a variety of different coaxial counter rotating rotor remote control toys with a sphere as a cage on the outsides. The examples they liked best were the spherical flight vehicle used by Japan’s Ministry of Defense and the Gimball, known of as the “world’s first collision-proof drone designed by the École Polytechnique Fédérale de Lausanne’s (EPFL) Laboratory of Intelligent Systems (LIS). With the shape of their Spherical Flying Machine established, the team moved on, researching the latest technology in spherical flying drones. While their sources weren’t limited to these three, they did inspire the spherical shape of the final design. As the design team are self-professed “hardcore fans of many science fiction shows,” they drew their inspiration from a few sci-fi sources they were especially enthusiastic about: The mapping drones in Prometheus, the flying camera balls known as “Kinos” in Stargate Universe, and the IT-O Interrogator droids in Star Wars.