Flying can be complicated when you don’t have a rudder-like tail.
Robot research has been looking to the animal kingdom for inspiration—and a new bio-mimicking robot tackles one of nature’s most irritating pests to prevent their real life counterparts from pestering plants.
In research published today in Science, a new fruit fly-inspired bot, called the DelFly Nimble, tested the capabilities of robots flying without tails as rudders. In the process, they discovered how fruit flies and other similar insects can stay aloft without a rudder-like tail.
“The robot is inspired by flying insects, such as fruit flies, in the way it is controlled,” says Matěj Karásek of the Delft University of Technology and lead author on the paper. “The rotations of both the robot and a fruit fly around their three body axes are controlled through adjustments of the wing motion of individual wings.”
To control the bot in flight, researchers tweaked the angle of its wings individually by rotating them forward or backward in relation to its body, or twisting them along the axis of its body. In the process, they learned about how fruit flies control their flight patterns and evade danger.
“Interestingly, we have observed a rotation around the third axis (yaw), which was not intentionally controlled by the robot, but was instead a result of a passive coupling effect,” Karásek says. “We discovered that this effect occurs when we adjust the wing motion to pitch and/or to roll only while moving. This effect, which is not present when standing still (hovering), is likely to be present not only in fruit flies, but potentially also in other flying animals with flapping wings.”
Guido de Croon, a co-author on the paper also at Delft, points out that the robots could be used to monitor actual fruit for ripeness—in effect, an artificial fruit fly intercepting real fruit flies before they can damage a crop.
“They can use an onboard camera to spot whether fruit is already ripe, or to see whether plants are under stress and need more water or nutrients,” de Croon says. “On the long term, they may even pollinate flowers.”
The bots also have a soft wing structure, making them safe to work around humans. But in order to bring the bots to the greenhouse, a few more things need to happen. de Croon says they need to be scaled down in size. This may involve wholesale redesigns of certain components that haven’t been miniaturized well before. “We will have to invent new mechanisms at a smaller scale, while hopefully still achieving the same agility as with the DelFly Nimble,” de Croon says.
The bots will also need to be smarter. The idea is that several of them at a time might monitor a greenhouse. They’ll need to navigate around each other, and maybe sometimes work in tandem. “We want to work towards a full navigation solution, so that the robot can explore even unknown areas and then come back to its starting position or charging station, without any human help,” de Croon says.
But if that future comes, you’ll have to take a little bit of time to make sure you’re not swatting at the wrong kind of fly.