Morphing Wing and Tail Give New Drone Exceptional Flight Agility

Inspired by the northern goshawk—a fast, strong raptor that flies easily through forests—researchers from the Laboratory of Intelligent Systems at EPFL, led by Dario Floreano, have developed a next-generation drone.

The researchers closely studied the shape of the bird’s wings and tail, as well as its flight behavior. This data was then used to design a drone with similar characteristics.

Goshawks move their wings and tails in tandem to carry out the desired motion, whether it is rapid changes of direction when hunting in forests, fast flight when chasing prey in the open terrain, or when efficiently gliding to save energy.

Enrico Ajanic, Study First Author and PhD student, Floreano’s Lab, EPFL

“Our design extracts principles of avian agile flight to create a drone that can approximate the flight performance of raptors, but also tests the biological hypothesis that a morphing tail plays an important role in achieving faster turns, decelerations, and even slow flight,” noted Floreano.

A Drone that Moves its Wings and Tail

In 2016, the engineers developed a bird-inspired drone with morphing wings. Their latest scaled-up model has the ability to adjust the shape of its wing and tail with the help of its artificial feathers.

It was fairly complicated to design and build these mechanisms, but we were able to improve the wing so that it behaves more like that of a goshawk. Now that the drone includes a feathered tail that morphs in synergy with the wing, it delivers unparalleled agility.

Enrico Ajanic, Study First Author and PhD student, Floreano’s Lab, EPFL

The drone quickly changes direction, flies slowly without falling to the ground, and decreases air resistance while flying fast by altering the shape of its wing and tail. A propeller has been used for forward thrust instead of flapping wings since it is more efficient and renders the new wing and tail system applicable to airplanes and other winged drones.

Winged drones are more advantageous than quadrotor designs because their flight time is longer for the same weight. But quadrotors tend to have higher dexterity, with their ability to hover in place and make acute turns.

The drone we just developed is somewhere in the middle. It can fly for a long time yet is almost as agile as quadrotors.

Dario Floreano, Scientist, Laboratory of Intelligent Systems, EPFL

This blend of features is particularly beneficial for flying in forests or between buildings in cities.

Opportunities for Artificial Intelligence

It is not simple to fly this latest type of drone as a huge number of wing and tail configurations are needed.

To leverage the flight abilities of the drone to the fullest, Floreano’s group plans to integrate artificial intelligence into the flight system of the drone so that it can fly semi-automatically.

Journal Reference:

Ajanic, E., et al. (2020) Bioinspired wing and tail morphing extends drone flight capabilities. Science Robotics. doi.org/10.1126/scirobotics.abc2897.