by Steve Bush
STANFORD, CA—U.S. and Swiss researchers have created a miniature multi-mode drone that can act as a tug, dragging 40 times its own body weight over obstacles—while helicopter-style aerodynamic lifting would only allow ~2x to be moved.
Called FlyCroTug, its operation was partially inspired by wasps.
“Wasps can fly rapidly to a piece of food, and then if the thing’s too heavy to take off with, they drag it along the ground. So this was sort of the beginning inspiration for the approach we took,” said Mark Cutkosky of Stanford University, which worked with the École Polytechnique Fédérale de Lausanne.
Not only do they drag it along the ground, but through the 3D environment—and this is what FlyCroTug can do.
The drone has a winch, on the end of whose cable can be attached various custom hooks and adapters.
This arrangement allows it to hook the object to be moved, fly away paying out cable, and then land and tug the object towards it.
For example, two FlyCroTugs were used to open a door, by hooking the lever-type handle, flying down to the floor, pulling the handle till the lock unlatched, then further pulling to open the door.
In another exercise, a single drone flew to the top of a structure and hauled up a camera to view inside.
To get traction on smooth surfaces, the feet of the drone are covered with a micro-structured surface inspired by that which covers gecko toes – which allows geckos to walk up glass. For gripping rough surfaces, there is also a row of 32 small fish-hook-like barbed spines on the drone body.
For other functions there are various other attachments that can be picked up, such as landing wheels.
“People tend to think of drones as machines that fly and observe the world, but flying insects do many other things—such as walking, climbing, grasping, building – and social insects can even cooperate to multiply forces,” said Dario Floreano of EPFL. “With this work, we show that small drones capable of anchoring to the environment and collaborating with fellow drones can perform tasks typically assigned to humanoid robots or much larger machines.”
Next, the team aims to work on autonomous control, and the logistics of operating several vehicles at once.
This research was published as ‘Forceful manipulation with micro air vehicles‘ in Science Robotics.