Flying and rolling drone will map underground mines on its own
A drone that can switch between flying and rolling could soon be exploring underground mines without the aid of a human pilot.
In open air, drones can navigate autonomously using GPS, but these satellite signals don’t penetrate deep underground, meaning robot spelunkers require human pilots.
Ahmed AlNomany and his colleagues at Swedish company Inkonova are working on an alternative. “It’s complicated because we are trying to invent another way of positioning using bits and pieces of technologies,” says AlNomany.
Having a view of its surroundings is the first step. Using laser scanners and a technique called SLAM, which calculates the distance between the drone and nearby objects, it will build up a map of its environment. And it can do so quickly.
The company recently used its manually operated drone, TILT Ranger, to map an underground mine in Mali using SLAM. In just 10 minutes, they were able to virtually reconstruct a section of the mine with a volume of roughly 30,000 cubic metres – about a third the size of London’s Royal Albert Hall. “It’s not a big challenge to capture such zones quickly,” says AlNomany.
Building a picture
Now the firm’s new autonomous drone can combine its map with additional input from sensors, such as an accelerometer, to position the drone and move without GPS. So far, during preliminary tests, it has been able to stabilise itself on its own in the air.
When it encounters unusually shaped space, it has a backup. Equipped with wheels, the drone can move along the ground and tilt to fly or roll at an angle if needed. “If it is near a wall, the drone will adapt to it and climb it instead of flying,” says AlNomany.
Adriano Mazzini at the University of Oslo in Norway thinks that automated drones are now the ideal choice to explore dangerous environments. “Relatively lightweight and high-performing tools can now be added to them,” he says. He recently sent a drone over the erupting Lusi mud volcano in Java, Indonesia, to sample gas, water and mud – something that would have been unthinkable just a few years ago.
Inkonova’s drones are of interest for other GPS-deprived environments too. The company was recently contacted to map a decommissioned nuclear plant. However, the mission was aborted through concern that the drone’s propellers would disperse potentially radioactive dust inside. “We didn’t pursue it further, but we would like to adapt Tilt Ranger for this purpose,” says AlNomany.