Novel Drone and Propulsion System Doubles Flight Time
Advances in drone technology are making inspections of inaccessible spots easier. A novel drone developed by EPFL start-up Flybotix is unique and best suited for inspection. Equipped with just two propellers and an advanced stabilization system that allows it to fly for twice as long as conventional models. This plus the drone’s small size, makes it perfect for inspecting hard-to-reach parts of industrial facilities such as ducts.
Small drones have limited flight time due to their heavy batteries and relatively inefficient propellers requiring the small drone’s battery has to be regularly recharged or replaced for longer missions.
To address this problem researcher Samir Bouabdallah at EPFL and ETH Zurich, has come up with an inventive propulsion system modelled after those used by helicopters. His design, marketed through his start-up Flybotix, uses just two propellers and an algorithm-based stabilization mechanism, giving his drones “the aerodynamic performance of a helicopter and the mechanical stability of a quadcopter.” Bouabdallah has decided to explore opportunities at the CES Asia conference and the Venture Leaders China program in China recently.
Two rotors guided by stabilization algorithms
A drone’s flying time is proportional to its size—the smaller the machine, the less time it can spend in the air, as Bouabdallah says “Drones with four rotors are highly stable, making them reliable and easy to use.” But as these drones get smaller, their propellers become increasingly inefficient. That, combined with their limited battery capacity, explains their abbreviated flying times.
One solution could be to use a completely different kind of propulsion system – for example, by reducing the number of propellers from four to two engineers can make each propeller longer and the rotor more efficient. This will also reduce the amount of power required, meaning the same-sized battery could run for a longer time. However up until now, drones with two propellers were generally less stable and harder to manipulate. Bouabdallah’s design employs a ring-like structure—around 30 centimetres in diameter—in which the propellers are stacked on top of each other in the centre and turn in opposite directions. His drones look more like flying saucers than the conventional drone designs one is used to seeing.
Conventional helicopters use a complicated transmission system that enables pilots to control the blades and maintain the aircraft’s pitch- but this system is heavy, cumbersome and requires a considerable amount of maintenance. Bouabdallah’s drones can be piloted just as easily as quadcopters, using a conventional remote-control device, thanks to another innovation of his drones’ stabilization mechanism. However, Bouabdallah has developed an algorithm that offsets the two rotating forces and serves the same function as a helicopter’s transmission system.
Additionally, Bouabdallah’s drone has a unique transmission system and foam covering its outer ring, so can bounce off of obstacles without breaking. The first application that Flybotix will target is inspecting dangerous or hard-to-reach areas. Encouraged by the immense positive feedback on their technology while in China last month the team made some promising contacts and are hoping to launch their drones in the Chinese market soon.
