The shorter a drone's propellers, the less efficient they are at keeping it airborne. That factor, along with compact, low-capacity batteries, is the reason that small drones can't fly for very long. A new two-prop drone, however, is claimed to deliver twice the flight time as similar-sized quadcopters.
The prototype is being developed by Swiss startup Flybotix, which was spun off of Switzerland's EPFL research institute. Its founder, Samir Bouabdallah, also developed drones at ETH Zurich.
Measuring about 30 cm wide (12 inches), the ring-shaped drone has two counter-rotating horizontal propellers stacked one above the other within its foam body. Because those props are longer than those that would be used in a same-size quadcopter, they provide more lift. Additionally, because the battery is only powering two motors instead of four, it doesn't run out as quickly.
Specially-developed algorithms are used to stabilize and control the drone, by monitoring and adjusting the rotational speed and tilt of the propellers. This setup is similar in purpose to the transmission system that helicopters use to control their pitch, although it's claimed to be much simpler and lighter, and reportedly makes the drone as easy to operate as a regular quadcopter.
And in the event that pilots do accidentally bump the aircraft into things, its foam body should cause it to harmlessly bounce off. With that in mind, one of its main planned applications is the inspection of hard-to-reach areas within industrial facilities. The prototype can be seen in action, in the video below.
Flybotix hopes to have a commercial product out soon, initially in the Chinese market. It may ultimately face some competition from another ring-shaped dual-prop drone, made by Canada's Cleo Robotics.
Source: EPFL
