Internet of Things in mining
As part of our commitment to industry transformation, we in Ericsson engage in projects in many different industries. Maybe contrary to popular belief, mining is an industry with a lot of potential for transformation. ICT can help mining industries improve productivity, safety, work force satisfaction and environmental impact.
Some time ago we wrote about our joint research project on connected mining but we don’t want to stop there.
At this year’s IPSO Challenge in Silicon Valley – by some called “the world championships in connected things innovation” – a smart rock bolt for use in mining caught widespread attention. This innovative product has been developed by a team headed by Associate Professor Jens Eliasson at Luleå University of Technology (LTU) and proudly mentored by myself.
So, what is a rock bolt and what’s the big deal about connecting it?
In mines, train tunnels or any construction involving large cavities in rock you need to reinforce the walls and the ceiling quickly after the digging or blasting is completed. Already a few hours after a tunnel has been created even a solid rock ceiling will start to slowly collapse due to the huge pressure from above and the lack of support from below. This is addressed by inserting large numbers (sometimes only 0.5m apart) of long (2-4 meters) metal rods in the walls and ceiling of the cavity. The rods are inserted in deep, drilled holes and fixated by injecting liquid concrete at high pressure.
Technically, the rock bolt stabilizes the tunnel by distributing the stress evenly along the length of the bolt, i.e. transferring the load from the unstable surface to the stable interior of the rock mass. Before the invention of rock bolts, mines where typically reinforced with wooden structures (like you see in old western movies) and cave-ins were more rule than exception.
Rock bolts are big business. A medium size Swedish mine could consume 100,000 bolts per year and the global market could be as high as 100,000,000 per year. They are mounted using powerful rock drills that also inject the high pressure concrete.
Rock bolts are “mission critical”. If one or several bolts in a tunnel fail, a cave-in could be the consequence, resulting both in production outage and loss of expensive equipment. Or even worse, human lives.
Although critical for the safety and stability of the mine, there is no simple way to determine the “health” of the rock bolt from the tunnel. A rock bolt may snap due to overstraining, or simply lose its grip on the rock, without any visible changes.
The smart rock bolt team has come up with an innovative product concept of adding a strain sensor and an intelligent, connected “head” to a traditional rock bolt. The “head” contains both sensors and electronics that allow the rock bolt to sense changes in bolt strain, vibrations etc.
Future extensions may be to introduce additional sensors such as gas and fire, both very dangerous in mines.
The smart rock bolt electronics is extremely energy efficient and will run for years on a single non-rechargeable battery cell. With up to a million rock bolts installed in a large mine, battery replacement is not practical. However, this is not really a problem since rock bolt failures typically happen within a few months of installation, so a rock bolt that has been healthy for a year has a very high probability of being problem free for the foreseeable future.
The smart bolt communicates with surrounding bolts and automatically forms a mesh network, allowing all bolts in a tunnel to share and forward data. This "swarm" connects to a gateway that uses 4G, Wi-Fi or plain wired Ethernet to connect each bolt to a cloud service. The bolt head also has powerful LED lights that can indicate both normal operation as well as different levels of warning. Other than just demonstrating status, the LED can be used for other valuable purposes, such as clearly directing personnel to the nearest exit during a power outage or an emergency evacuation.
Besides the innovative product itself, one of the key reasons the team became a finalist was that the system is based entirely on IP and open standards such as 6LoWPAN, CoAP, OMA LWM2M, IPSO Smart Objects and IPsec. Ericsson being one of the founding members of IPSO Alliance, these are of course also standards promoted by Ericsson. Ericsson strongly believes in open and interoperable standards for making the Networked Society a reality.
Oh, I almost forgot. The Smart Rock Bolt won first prize. In Silicon Valley.