Flat motor technology powers a dual-propeller drone

EPFL start-up Flybotix is showcasing its dual-propeller drone today at Xponential, the world’s largest tradeshow for unmanned and autonomous systems. Intended for inspecting hazardous locations, this flat-engined aircraft is quiet, saves flight time, and is also capable of flipping like a turtle if it finds itself upside down on the ground.This drone propellers were developed through a joint effort between Flybotix and a major company in EPFL’s Innovation Park. The new drone is expected on the market in 2021.
Flybotix dual-propeller drone © 2020 Alain Herzog

A dual-propeller propulsion system gives Flybotix’s drone unmatched flight time and very low noise levels. An initial prototype was unveiled in the summer of 2019. The finished product is fitted with a custom-designed ultra-flat motor developed in partnership with Maxon, a major company located in EPFL’s Innovation Park. The new drone is being presented today, online, at Xponential, the world's largest trade show for unmanned and autonomous systems. Flybotix is planning a market launch in early 2021.

Twenty minutes’ flying time and flat motors

Currently, drones that are small enough to maneuver in tight spaces like ducts can stay airborne only for about ten minutes. To save energy and extend flight time, Flybotix’s drone has been fitted with a propulsion system that is similar to the one used on helicopters, which have unparalleled aerodynamic performance. Because the bulky mechanical stabilization system is replaced with algorithms, the flight time is twice as long.

Engineers had to redesign the motor’s shape in order to superimpose the twin propellers and free up space for payloads. EPFL's Innovation Park is home to more than 200 start-ups as well as many branches of large companies, putting them in close proximity to EPFL’s fast-paced and flourishing innovation community. A partnership with one of the large companies, Maxon, whose parent company is based in Obwalden, produced the customized motor. “The stationary portion of the gear system has been inverted. This enabled us to flatten it, leaving more space between the propellers,” says Olivier Chappuis, head of miLab, Maxon’s innovation lab at EPFL. Combining Maxon's expertise in motors with Flybotix’s creative energy led to the rapid development of the advanced propulsion system. “We get a great deal out of working with start-ups. They need new systems developed in record time, which spurs us to innovate more quickly. And our findings can be used in other applications too,” says Chappuis.

Like a turtle flipped on its back

The new drone includes a number of other innovations, such as a patented cage system that allows it to navigate through obstacles and right itself when upside down. This system – inspired by turtles – triggers a pendulum movement; the inverted drone rocks back and forth for a few seconds until the swinging movement returns it to an upright position.

Despite the pandemic, 2020 was a productive year for Flybotix. The firm raised CHF 1.5 million in investments, enabling it to expand its headcount from four to ten people. Its drone is now ready for commercial production and will be assembled in Switzerland. One of the first applications will be monitoring hazardous sites or inaccessible locations. Other start-ups in the region are also developing drones with similar applications and characteristics. “We are aware of them, and this will not affect our market launch,” says Samir Bouabdallah, Flybotix CEO. “On the contrary, it fosters a competitive spirit which benefits everyone – similar, for example, to the luxury watch industry.”