Researchers at TU Delft's Micro Air Vehicle Laboratory (MAVLab) have developed a flying robot inspired by insects. The robot was presented for the first time in Science (14 September 2018). In collaboration with Wageningen University & Research, a series of experiments were conducted with this autonomous and highly manoeuvrable winged robot. As a result, we now better understand how fruit flies perform their lightning-fast escape manoeuvres. The development of this robot enables new studies of insect flight movements. In addition, due to the exceptional flight characteristics of the robot, all kinds of new applications for drones are conceivable.
Animals that can fly do so by rapidly moving their wings up and down. Small species, such as insects, can therefore hover close to a flower but also take off immediately when in danger. Biologists have always been fascinated by flying animals.
They study not only the complex wing movements and aerodynamics, but also their senses and locomotor apparatus during agile manoeuvres. Flying animals have also recently been a source of inspiration for researchers working on the development of lightweight drones that are agile, economical and ever-smaller.
Extremely agile flying robot
Researchers at TU Delft's Micro Air Vehicle Laboratory (MAVLab) have developed a new robot inspired by insects. Its performance is almost inimitable and yet it is quite simple to make. The robot's wings move up and down 17 times per second. In doing so, they generate the necessary lift that allows it to stay airborne. With minor adjustments to the wing movements, the robot can be controlled. Like fruit flies, the robot's control mechanism is very effective. This not only allows it to hover and fly in all directions, but it is also highly manoeuvrable.
"Our robot has a top speed of 25 km/h and can perform sharp manoeuvres, such as flips of 360 degrees, as in a looping or rolling flight," said Matěj Karásek, the first author of the research and chief designer of the robot. "In addition, with a wingspan of 33 cm and a weight of 29 grams, it is extremely efficient, allowing it to hover for 5 minutes or fly more than a kilometre on a fully charged battery."
Escape manoeuvres of fruit flies
The robot is not only an autonomous microdrone, but its flight characteristics and programmability also make it very suitable for conducting research on insect flight. TU Delft is therefore collaborating with the University of Wageningen. "When I first saw it flying, I already found that its flight pattern resembled that of insects. I immediately thought: we can use this robot to research the dynamics of insect flight," said Dr Florian Muijres of the Experimental Zoology chair group at Wageningen University & Research. Because of his previous research on fruit flies, the team decided to programme the robot so that its flight pattern resembles that of these insects during escape manoeuvres, such as when you try to swat them to death.
The manoeuvres performed by the robot resembled those of fruit flies. The robot could even show how fruit flies turn and rotate, giving them the best chance of escape. "Unlike normal experiments with animals, we now had full control over what was happening in the 'brain of the laboratory animal'. This allowed us to identify and describe a new passive aerodynamic mechanism. This mechanism helps the flies, but possibly other flying animals, to maintain control while making razor-sharp turns," Karásek said.
Click on the picture below to see a video of the robot:
Possible future applications
MAVLab has been working within the DelFly project for more than a decade to develop flying robots inspired by insects. Dr Guido de Croon, scientific leader of the MAVLab, says: "There are many application areas to consider for insect-inspired drones. They are light, safe and a lot more efficient than traditional drones, especially for drones with this kind of small size. Until now, these flying robots have not fully realised their potential because they were either not agile enough - like our DelFly II - or too difficult to build." The robot in this study, the DelFly Nimble, builds on existing production methods, is composed of standard parts and has a long flight time, making it interesting for practical applications.
The DelFly Nimble is being further developed within the TTW project "To be as nimble as a bee", a collaboration between TU Delft and the University of Wageningen, and funded by NWO.
Source: TU Delft.
Photo credit: MAVLab TU Delft.
