"Armchair Mining," Feature Article, May 2003

FEATURE FOCUS: Automated Controls

armchair mining

Technology is getting miners out of the tunnels and into the control room.

by John DeGaspari, Associate Editor

Underground mining is dusty, noisy, and dangerous work for those who run the big drills and haulers in the tunnels, and it is costly for the companies that operate the mines. Each day, miners descend thousands of feet into the dark bowels of the earth to operate huge rigs that drill, blast, and haul rock that contain ore.

Over the last several years, however, a few mining companies have begun working with remotely operated machinery. These are the first steps in moving the most vulnerable link—human operators—out of harm's way, while at the same time increasing the mine's competitiveness.

A teleoperator in an Inco control room is able to manipulate loading in a mine 10 miles away.

Overall, the mining industry does not have the highest injury and illness rate among industries—at least in the United States. Fifteen miners have been killed so far in coal, metal, and non-metal mines in the United States as of April this year, according to the Mine Safety and Health Administration of the U.S. Department of Labor. In 2001, the rate of fatalities in underground mines in this country was less than one per 100 workers. In terms of raw numbers, mining has shown an overall decrease over the past decade, with 181 fatalities in 1992 and 156 in 1999. That is much lower than agriculture, forestry, and fishing, which had 816 fatalities combined. Even retailing had a higher number of job-related deaths—515.

Remote-controlled mining, known as teleoperation, could help drive down injury further by removing miners from hazardous areas and, at the same time, could significantly increase productivity, according to some experts. While teleoperation is not yet widespread, it has been implemented by a handful of companies. They often view it as part of a larger strategy to automate their operations.

As companies and automation experts bring teleoperated machinery into working mines, they are facing questions of how this evolution will affect day-to-day operations, worker responsibilities, and mine designs. Figuring out the best ways to handle those issues could help pave the way for wider implementation.

WHY IT MATTERS

John Steele, an assistant professor of engineering at the Colorado School of Mines in Golden, views teleoperation as the first step to wider automation in mines. He believes that the lives of one or two miners could be saved a year, simply by moving them out of harm's way. It would reduce contact with other health hazards as well.

Overall mining automation could result in significant cost savings, Steele said. Travel time to and from the surface can take hours, reducing productive work by as much as 50 percent in a typical eight- or 12-hour shift. "You could immediately double productivity by automating these machines," he said.

And there are other benefits, as well. For example, large, power-hungry fans that control the flow of air through the mines could be eliminated if miners were no longer underground, and so an expense could be eliminated.

Greg Baiden, a professor of engineering with a chair in robotics and mine automation at Laurentian University in Sudbury, Ontario, believes that mining automation requires fewer human and capital resources to do the same amount of work. Fewer supplies are required because the mine operates more effectively. And because it takes less work to get the job done, the mine operates faster. Those factors could also result in improvements in quality.

Luc St-Arnaud is the general manager of SIAMtec, a Saint-Laurent, Quebec, mining automation supplier partly owned by Noranda Inc., a Canadian mining and metals company. He believes that teleoperation provides more flexibility in getting the ore from the mine. It allows access to areas that would be off limits to manned vehicles. "It is adapting the mine design so that you could relax your safety criteria to standards that are okay for a vehicle, but not okay for a vehicle with an operator on it," he said.

STAYING IN TOUCH

Two developments in recent years have dovetailed to make teleoperation in mines possible, according to automation experts. One is a robust communication backbone in the mine, capable of handling data, voice, and video signals. The other is "smart" mining equipment, outfitted with on-board computers and a host of sensors.

Having better communications networks, comprising
cable and wireless, is the key development that opened the door to teleoperated mining, according to Baiden. In 2001, he started a mining automation company, Penguin ASI, in Sudbury. Prior to that, he headed the mining automation program at Inco Ltd. of Toronto, when the company developed a high-bandwidth telecommunications system that would work in rock tunnels. While bandwidth is a limited commodity on the surface, the full radio frequency spectrum is available underground, where it is essentially self-contained for use in the mine. In his view, this is one reason that teleoperation may be more feasible for underground mining than for open-pit mining.

A load-haul-dump vehicle in LKAB's iron ore mine in Sweden scoops rock with the help of a teleoperator working off-site; the vehicle does hauling and dumping automatically.

Teleoperation uses a combination of radio communication, TV cables, and fiber optics. Fabien Miller, marketing director of SIAMtec, said that teleoperation advanced along with the improvements in communication. First attempts in the mid-1990s, using a standard television signal, were plagued by poor image quality, and the vehicles had to be controlled at close proximity. By the latter part of the decade, dedicated communication lines for television and data improved communication between the vehicles and control rooms. Since then, digital communications have allowed both signals to be transmitted over one communications line, he said.

Teleoperation is really a semi-automated process, in which an operator manipulates equipment from a distance. Guidance systems, based on either optical systems or lasers, are installed underground, allowing vehicles to travel through tunnels autonomously. The company has a distribution agreement with Atlas Copco Wagner, a Portland, Ore., manufacturer of mining vehicles.

Automated Mining Systems in Aurora, Ontario, supplies electronic products for robotic automation of underground mining. It has worked with Inco for 10 years, automating operation of load-haul-dump vehicles known as LHDs, haulage trucks, and stationary drills, according to Automated Mining's president, Jack Purchase. LHDs are low-profile, underground front-end loaders that are used at the mining face, where loose rock is scooped up and transported to another location in the mine where it is dumped.

LHDs typically travel autonomously to and from the working face, although loading is done with the help of a human operator, who manipulates the machine from a remote location. Drilling machines, too, are operated remotely after being put in position by miners. The miner controls the equipment from an adjustable chair similar to those found on high-end trucks. The console is equipped with foot pedals, joystick, touch screen panels, and television monitors. The operator who sits in the control room can actually hear the motors of the vehicle, Purchase said. The vehicle carries its own local area network through which its functions are controlled.

LKAB, a Swedish company, installed remote controlled drill rigs at its Kiruna mine in the 1990s. Mining automation requires coordination of maintenance activities with production cycles.

AMS builds its own electronic components designed to withstand shocks up to 50 g and vibrations that are worse than the Saturn liftoff, Purchase said. Because underground vehicles encounter air pressure changes while traveling through the mine tunnels, controllers are gas pressurized to keep acidic water from passing through seals.

Television cameras on the vehicles serve as video feedback to the teleoperator when loading the bucket and may also be used as a vision system by the on-board computer, allowing it to perceive its surroundings. Laser scanners act as range finders, guiding the vehicles as they roll through the tunnels.

Purchase said that a typical LHD might be outfitted with as many as 150 sensors of one type or another. These include sensors to measure hydraulic or engine pressure, air pressure sensors on tires, and accelerometers to sense rocks lying in the vehicle's path. In the interest of minimizing failures, the company tries to keep the number of sensors on a vehicle to what is really necessary.

Meanwhile, Steele of the Colorado School of Mines is working on stereo vision to create a three-dimensional model of the LHD's surroundings. The goal is to improve teleoperated loading as well as to enable automated loading, he said.

A TALE OF TWO MINES

Inco teleoperates drilling equipment and LHDs at its Stobie nickel mine. The mine remotely operates four long-hole carbide drills from a control center 10 miles away. It also remotely operates two LHDs, which move 3,000 tons of rock per day on a 24-hour, seven-day-a-week schedule. The LHDs have been in service for about a year. The addition of automation-related components has increased downtime of the machines by no more than 3 percent, said Al Akerman, supervisor of mine automation, diamond drilling, and raise boring.

Inco has looked at ways that teleoperation could improve mining operations, and where it could be applied. The mine has been working on ways to automate digging tunnels, known as drifts. It's a labor-intensive and time-consuming process, in which a jumbo drill cuts holes into the face. The holes are filled with blasting emulsion, which is detonated. Then the loose rock is scooped up, hauled, and dumped in an operation known as mucking. Shoring up the walls with shotcrete, a cement-like material, follows the mucking operation.

In Akerman's view, teleoperation could save time in this process by eliminating some delays that are inherent in it. Conventional procedure is to wait 18 to 24 hours after shoring up a site before allowing workers to re-enter it. By eliminating workers from the site, equipment could be moved in sooner, assuming the mine is willing to expose the equipment to risk, he said. Inco has worked with Maclean Engineering of Collingwood, Ontario, to develop an automated loader to fill drill holes with explosive emulsion. The design incorporates robotics, machine intelligence, and vision recognition. The companies plan to bring the machine underground for testing.

Akerman sees advantages in safety and productivity in teleoperation. One person in a control room can manipulate two or three pieces of equipment at a time, he said. Commutation of miners to and from work sites, some of which are 7,000 or 8,000 feet deep, has been eliminated, saving as much as two and a half hours out of an eight-hour shift. Machinery could be operated 20 hours a day, allowing time just for refueling and maintenance.

Distance has basically become irrelevant in teleoperation. Inco has run demonstrations controlling machinery at its Sudbury mine from roughly 600 miles away, in Montreal. Response time of the equipment is 100 milliseconds, said Akerman. No major modification to the equipment is required for teleoperation, since much of the machinery that Inco specifies is already capable of line-of-sight operation, he said. However, with no miners nearby, the equipment must be able to detect fire by itself. The machinery is equipped with fire suppression systems that can be triggered by off-site operators.

A Swedish company, LKAB, which has introduced automation to its iron ore mines in Kiruna and Malmberget, started using the first driverless underground trains to transport ore at its Kiruna mine in 1970, but has since expanded to remote-controlled drilling and loading and LHD operation. Kiruna has one large ore body, which required laying track for only one train to transport the ore. Between 1995 and 1999, Kiruna automated six drill rigs. Last year it automated half its fleet of LHDs, in which loading is directed by teleoperation, while hauling and dumping are fully automatic.

LKAB has established a goal of integrating its automated operations at Kiruna into a production center, where operators work with those responsible for support functions to coordinate a range of activities, such as pelletizing, rail transport, and shipping. One part of the plan is to allow machine operators and maintenance personnel to work together to better coordinate operations.

Carl-Erik Emmoth, superintendent of the sublevel caving and transportation level at Kiruna, said the mine has teleoperated as many as eight out of 15 LHDs, but is presently upgrading several of the machines to increase the stability of the on-board communication and navigation systems. The goal is to increase operation of the vehicles from 14 hours a day to at least 20 hours.

The mine has installed a gating system to keep miners out of the LHD's path. Maintenance is an issue that must be addressed with automation, said Emmoth. He feels that maintenance workers have to coordinate better with production cycles, and not make surprise visits that cause unscheduled production stoppages.

Rob Rennie, vice president of engineering and product development at Maclean Engineering, said that mine automation still has a long way to go in some respects. "There is no clear vision of doing this," he said of teleoperation. For example, there might be alternatives to drilling and blasting in some mines, he said. One challenge in automating underground mining equipment is the corrosive and dirty environment, he said. Another is confirming that the equipment is where it is supposed to be in the mine.

One of the driverless underground trains that has carried ore since 1970.

The effect that automation would have on jobs is a sensitive issue. At Kiruna today, one operator can control six drilling rigs, Emmoth said. He noted that the mine employed 3,000 workers in 1983. Today that number stands at around 1,700, including those working in teleoperation plants and workshops on the surface.

At Inco, Akerman does not foresee completely unmanned mines anytime soon. One issue is maintenance. A lot of equipment, once underground, never sees the light of day again, and mining equipment in general is inherently unreliable, he said. "Until we get better mean time between failure on components, we will be needing a lot of interaction on this equipment," he said. Repairs are often required before the 250-hour inspections that are mandated by the Canadian government.

Joe Main, health and safety administrator of the United Mine Workers of America in Fairfax, Va., acknowledged that technology such as teleoperation has affected the mining industry dramatically for years, and it has improved mining conditions. But he is wary of job losses. "There is no question that there are hazards in mining," he said. "But we can operate the mines safely if we apply the right means and technology to do that, without replacing the workers in the workplace." The union represents miners in the United States and Canada.

CHANGING CULTURE?

Greg Baiden believes the technology is in place for mining automation to work. The big step, in his view, is to change the way that mining business is done. Baiden describes his start-up, Penguin ASI, as a telecontracting business, which would build and operate a control room and supply the equipment and labor that would remotely operate mines. He said the company is working with five mining companies, some of which operate more than one mine.

He sees a power shift occurring in the mines. If a traditional mine running six LHDs would require 24 workers and a foreman, teleoperation might require only two workers who actually are foremen in their own right. Mines, he said, need to come up with a strategic plan to apply technology to their operations. He acknowledged that this could be a difficult change in existing mines, and he is setting his sights on mines with new ore bodies to develop. In his view, all the equipment in the mine could potentially be teleoperated.

Baiden compares what is going on in the mining industry today to mechanization in the agricultural industry a century ago. He believes that the payoff of applying technology such as teleoperation and automation could be huge over the life of a mine.