Researchers Turn to Insects for Inspiration in Building a Self-Righting System for Fixed-Wing Drones

A team of researchers have taken inspiration from nature to design an add-on for fixed-wing drones, which work to provide additional lift and to self-right the drone should it flip onto its back: Elytra.

"Micro Aerial Vehicles (MAVs) are being used in a wide range of applications such as surveillance, reconnaissance, inspection, and search and rescue," the team writes in the abstract to the paper. "However, due to their size and mission profiles, they are prone to tipping over, jeopardizing their operation."

"Self-righting is an open challenge for fixed-wing drones since existing research focuses on terrestrial and multicopter flying robots with solutions that increase drag and structural weight. Until now, solutions for winged drones remained largely unexplored."

The solution explored by the team: Elytra, secondary shell-shaped wings found above the main wings of beetles. The team built artificial elytra from a hybrid of carbon fiber and Kevlar and attached them to an otherwise unmodified off-the-shelf fixed-wing drone dubbed Ely — and put them through their paces.

"The flight tests consisted of first dropping Ely onto the ground such that it landed in an inverted position," the team explains. "At impact, the elytra absorbed the landing loads and immobilized the drone. Then, the self-righting function was manually triggered. The pre-programmed self-righting function autonomously began after five seconds."

"The elytra are first swept back 90° and then pitched forward 180° to flip the plane into its upright position. After uprighting, the elytra move back to their flight position. Next the pilot engages full throttle and the plane takes off."

While the elytra add bulk, they also provide additional lift — which, the researchers claim, offsets the additional weight. They did, however, impact the drone's overall manoeuvrability.

The team's work has been published under open-access terms as an early access paper in the journal IEEE Robotics and Automation Letters; more information is available from IEEE Spectrum's coverage.