Swiss drone manufacturer Flyability has developed a unique solution to the challenges of underground mining. Its collision-resistant drone has completed several successful missions at the Lac des Iles mine in Ontario, Canada.
Until recently, the use of drones in the mining industry has largely been above ground, in the open air. From on high, drones and their paired software platforms can build a detailed picture of equipment stockpiles, materials and landscapes. It’s a great industrial IoT (IIoT) use case.
But exploring uncharted mines, deep underground, comes with challenges that generally aren’t encountered in the skies. Signal reception is a serious one, but there’s also the difficulty that advanced collision-avoidance vision systems experience in keeping a drone stable and on track in the darkness.
A drone for uniquely challenging circumstances
Unmanned Aerial Services has used Flyability’s Elios drone to explore every dark corner of the North American Palladium Lac des Iles mine.
That has been made possible by searching around the world for advanced solutions to the challenges that come with operating underground. First, Elios from Switzerland-based Flyabilty is unlike any conventional drone you will see on commercial missions.
Around its body and propellers is a carbon fiber cage that allows it to bounce off walls and remain in the air, just as an insect might. This comes in handy in scenarios where there is no light or GPS connection to help keep the drone steady. Being able to tolerate collisions is one thing, being able to adequately pilot a drone in such conditions is another.
“The stability of the drones is extremely impaired in a mine. You can’t just fly any kind of drone as [when] it goes beyond line of sight… you can only see what the drone sees,” Flyability’s marketing manager Marc Gandillon told Mining Today.
“If you’re in a very narrow space, there’s a high chance that you’ll hit something. Then you can break a propeller and then your drone is left there because there’s no way you can collect it. So the cage was necessary to be able to explore that kind of environment.”
Flyability had to look east for a connectivity solution, to leading drone manufacturer DJI. The drone industry giant was able to supply its Lightbridge 2 transmission system to be used with Elios.
The result was a crash-proof drone capable of flying up to 150 metres from its pilot without any loss of signal coverage, despite curved passages leading further underground and pitch-black tunnels – all while sending a continuous stream of footage back to its operator.
“The main problem that is quite sensitive is the signal propagation; to control the drone you need to have a radio signal connection between the drone and the remote controller,” said Gandillon. “The environment, a rocky or concrete environment, is constantly absorbing the signal’s energy so if you go too far away then you lose signal and you can’t bring the drone back.”
Mining vital data from inaccessible spaces
Underground mines are dangerous. After an excavation has taken place, the open cavern that remains needs to be refilled to prevent the area from caving in. This process is known as backfilling. It’s too dangerous to send people into these unstable areas, so one of the main tasks assigned to Unmanned Aerial Services’ co-founder Matt MacKinnon was to determine what needed to be done through remote exploration.
“In the past, it was a guessing game even at the most modern mines,” said Matt MacKinnon. “A very, very expensive guessing game.”
The Elios was able to perform an exploration task that would normally take a day or more in just an hour. The drone also provided new data that would otherwise have been impossible to gather, compared with the usual method of mounting a CMS laser onto a cable.
The result was proof that a rugged drone capable of working underground is a significantly better decision-making tool, not just a step up in safety. “How do you put a price on that?” said MacKinnon. “You’re in the hundreds of thousands, or even millions… you can spend millions to access an area only to find that it’s beyond rehabilitation.”