A small device, with an aerial the size of an adult’s forefinger and a wafer-thin circuit board the width and length of a matchbox, could crack open the problem of finding mine workers lost in underground rockfalls while keeping track of their vital signs, and herald a great leap in robotic mining and communications.
The unassuming device — which its inventor, Idrees Zaman, a visiting researcher from Germany’s Bremen University, says could be made much smaller and cheaper — will easily fit inside a mine worker’s helmet.
It could provide communication with similar nodes — ideally fitted to long bolts drilled into the ceiling to keep rock from shearing off and falling — placed along tunnel roofs or walls.
The battery-powered device could be made a lot smaller by drawing power off the battery pack used for cap lamps every mine worker has underground. Early cost estimates put the devices at less than R1,000 each, a fraction of the cost of low-frequency or high-frequency devices used for underground communications, Zaman says.
The device operates at 433MHz, a frequency that allows communications to travel through air, rock and broken rock. While tests are under way to determine the range of the devices that can also run off a mine’s alternating current, initial indications are that 10m is easily achievable, Zaman says.
"The mine of the future will have wireless communication and we are working on the possibility that this communication system will have more jobs. We are looking at reliable, multipurpose communication systems" Fred Cawood, Head of the Wits Mining Institute
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