Published in the January 2010 Australia’s Mining Monthly
As one of the world’s most safety conscious mining countries, Australia is dragging its feet on collision avoidance systems.
Underground coal miners, for example, do not even have access to an industry approved system.
Yet in countries where mine safety is often criticised, such as South Africa,approved systems are a requirement on all vehicles in underground coal mines.
With costly downtime a direct consequence of vehicle to vehicle, vehicle to pedestrian and vehicle to infrastructure accidents, mining companies are seeking to mitigate their risk.
In Queensland up to 50% of minesites already use a collision avoidance system.
Despite many of the state’s miners taking the issue upon themselves, Queensland mine safety and health commissioner Stewart Bell said a mandate requiring collision avoidance technology on minesites would likely be introduced by June.
“Every week, almost without fail, we would see issues where vehicles collide with each other,” Bell said.
The week before Australia’s Mining Monthly spoke to Bell, he said two large haul trucks had collided and there had been two other separate incidents involving light vehicles.
“We were lucky last week, because no one was injured,” Bell said.
“But we have had fatalities that have involved vehicles moving, particularly in underground coal mines, where they have moved and someone has been standing close beside them and they have been crushed against a coal rib.
“We have had fatalities in open cut coal mines where people have run into large vehicles in broad daylight.
“Once again, a collision avoidance system or proximity detection would have possibly alarmed the person to enable him to avoid running into the back of a large vehicle.”
With accidents a regular occurrence on mine sites the industry is calling for further research and development into effective forms of collision avoidance technology. It also wants the effectiveness of some of the systems being used tested.
A report from the University of Sydney titled Designing a User Interface for Improving the Awareness of Mining Vehicle Operators revealed technology had the potential to aid the operator in the tasks of driving and contribute to the overall safety of the mine.
However, the design and implementation of these systems and user interfaces are still being developed to a level that satisfies researchers.
Different intelligent transportation systems need to be deployed depending on the mining operation. A combination of technologies can often be the best solution – at least until a universal approach can be adopted.
Underground mining equipment typically works in confined spaces and in much closer proximity than on surface mines.
University of Queensland School of Mechanical and Mining Engineering automation engineer John Dudley said the close proximity placed significant demand on sensing technology as it became difficult to distinguish between standard operation and a potentially dangerous situation.
“The structure and physical properties of the underground environment can also have a very complex effect on the way radio waves propagate, limiting the application of technology that relies on knowing how such waves behave with a high degree of certainty,” Dudley said.
“The development and introduction of systems into underground coal mines in particular is further complicated by theneed to ensure intrinsic safety of all components.”
A number of technologies employed successfully on the surface in collision avoidance systems are rendered ineffective by the underground environment.
“A perfect example of this is GPS, which relies on signals from orbiting satellites,” Dudley said.
The underlying causes of collisions can be a combination of impaired awareness from cab blind-spots and poor visibility from natural elements; human factors such as poor training, distraction or fatigue; and equipment failures such as brake and communication outages.
“The functions a collision avoidance system must perform to truly improve safety are yet to achieve real clarity,” Dudley said.
“With currently exploited technology, it is very difficult to determine the location of people with high accuracy.”
Dudley said the advancements in radio frequency identification technology allowed for the growing sophistication of intelligent transport systems. The use of radio technology is being researched by the CSIRO.
RFID is a data collection technology that uses electronic tags and, depending on the type of tag and application, can be read at a varying range of distances.
“This is used for vehicles that can see each other to measure the distance between them, and can also be used for measuring vehicles out of sight or around a corner,” CSIRO research scientist Mark Hedley said.
Hedley is part of the information and communications technology centre in the wireless technology laboratory.
The Sydney-based group is conducting research and testing collision avoidance technology before it is ruggedised and engineered into a commercial product.
“Mining is the main one we’ve been looking at for collision avoidance, in fact, what we are generally developing is tracking technology,” Hedley said.
Fixed and mobile infrastructure can be fitted with RFID devices and then a radio frequency network of where everything is located can be determined.
CSIRO’s Wireless Ad Hoc System for Positioning, WASP for short, is a tracking system that forms the basis for collision avoidance and other applications in mining.
“The first thing about collision avoidanceis to know what’s coming,” Hedley said.
“We have done some evaluation underground already, and direct measurements are limited to line of sight,but as long as you form a network you cansee around corners or wherever else they might be as well, so you know things are coming.
“It’s not just collision avoidance, it is vehicle tracking, and once you do that you enable other benefits to the mine too.”
The transmissions use less power than a mobile phone, and can operate up to one kilometre away with line of sight.
“If you are trying to know where things are going around corners you need to have a sufficient escalation of the fixed infrastructure so you can get communication no matter where you are,” Hedley said.
“We had a target because we knew we wanted to develop a technology that had certain characteristics, we want it to operate well in what you might call radio propagation environments, typical of a cluttered or underground environment.
“We knew we wanted it to operate so it didn’t need wired connections to anything and we knew we wanted it to be accurate.”
The CSIRO has been contacted by a number of companies that tried other tracking products, found they did not work as advertised and faced challenges trying to get them working effectively.
The mining industry was seeking a quick solution to collision avoidance technology, Hedley said, however, the CSIRO set up long-term research to meet the challenges.
The organisation’s research has identified some faults in other technologies and systems on the market. It found that some standard GPS’ may only supply accuracies within a couple of metres.
One of the simplest systems is based on advanced radar technology to receive signal strength tracking. Hedley said there were high claims of what it could achieve, however the performance and accuracy were poor.
“Another type of system that has been deployed to some extent and been around for a while is RFID, that’s not actually continuous tracking,” he said.
Most commonly used for zone control, RFID can only provide detailed information if there is a reader at every single possible branch point. This, once wired up, can be expensive in terms of installation costs even though the electronic tags themselves are quite cheap.
“Whereas using a straight radio frequency tracking you have continuous tracking,” Hedley said. “A signal down a drive no matter how long it is, no matter how many branches there are, you still know where they are.”
WASP can operate on battery when being used by workers and is designed to also plug into power sources and vehicle electronics.
“The real challenge is to provide information in a natural way so that the driver does not have to take their eyes off the road,” CSIRO Earth Science & Resource Engineering research engineer Dr Patrick Glynn said.
“Drivers already have a lot on their hands and should not be overloaded with information.”
LSM Technologies owner Peter Woodford regularly participates in workshops and conferences about collision avoidance and described it as a hot topic that had been boiling away for the past year or two.
He has been invited to speak at an increasing number of events over the past two years, with more lined up next year as the subject gains momentum in the industry.
“The one that seems to cause a lot of accidents and fatalities is where we have vehicles running over people, vehicles running into vehicles and vehicles running into infrastructure, and they don’t seem to be going away,” Woodford said.
According to Woodford, the best technology to use can only be identified after a risk analysis of the site is complete, and needs to address three components – operator visibility, proximity detection and collision avoidance.
“There is a lot of technology out there to try and mitigate these incidents, but while they can add value, they’re not the thing they should be concentrating on in the first line of defence,” Woodford said.
“If we look at the number of incidences and high potential incidences, more than 95 per cent have a significant component of a blind spot around the vehicle.”
Vehicles travelling at low speeds, during rearward travel and in close proximity have been three consistent factors associated with collision risks and accidents.
Cameras are suitable for surface mining equipment when operator visibility is a significant issue.
“When we talk about the causes of these incidences and we look at what needs to be put as defence number one to resolve all this, it is basically a camera system,” Woodford said.
Where radio frequencies and GPS work at great distances and identify exclusion zones between vehicles and people, he argued there was only one international standard for operator visibility around a machine.
“Operator visibility is about providing closed circuit television systems.
“We need to resolve the main primary causes and significant factors and that is operator visibility.
“Give them vision and then, if you want, add a proximity detection device, or GPS, or radar as your back up.”
Suitable for safety practices in dusty and rugged areas, the CCTV system LSM offers has case hardened photo-chromatic lens that can change to a sunglass for anti-glare.
The lens is pressurised with nitrogen and helium for sealing to handle high pressure spray hoses, and chemically smoothened so dust will not obscure the view.
In underground operations, proximity detection systems and devices to determine the zones between vehicles and people are better options where a camera will not help.
“The desired function of collision avoidance systems is to provide an overarching layer of protection for people and equipment,” Dudley said.
“Collision avoidance technology is already, and will continue to be, integral to the automation of mining equipment and can help formalise and restrict the way people and equipment can interact. This is important as automated equipment and people work more and more closely together.”
Newmont Mining has been trialling several systems in both underground and surface mines at its operations in Australia, Peru, Indonesia and the US.
Newmont global director operations solutions Dave Goddard said he was not convinced there was one system available that offered a complete solution.
He said there were two major problems with technology available to the market.
“The majority of the systems out there are all or nothing systems,” Goddard said.
“By that I mean the systems require all equipment including light vehicles and to a certain extent humans, if that system supports it, to be equipped with something in order for the system to be functional.”
Goddard’s view refers to systems such as RFID or even GPS to an extent. If an employee forgets to wear an RFID tag, they effectively become invisible to the operator.
“The last [thing] you want is to become reliant upon the technology,” Goddard said.
“Then have something that is blind to that system or invisible to that system and then have an incident as a result to that.”
The second problem with existing systems, Goddard said, was they had not been thoroughly tested in the context of a working minesite in real life situations.
Like car and house alarms are ignored in everyday life, he believed operators would ignore collision alarms if they continually sounded during normal operation.
Goddard used the example of a haul truck backing into a shovel pit to be loaded.
“You have to have the context of the location of the two items, the context that it is in reverse and backing in, you have to have the context where the dipper is on the shovel and things of that nature,” he said.
“Otherwise if you are backing in just a simple radio alarming system is going to be going off the entire time during that normal operation.
“That alarm over time will just gradually be ignored by the operator because it’s alarming during normal operational procedures.”
Newmont has not set a timeframe to implement collision avoidance systems in its mines.
Goddard said the company wanted to complete more research and development to find what technologies best worked for it before making any decisions.
“I think it is really early in this marketplace,” he said.
“I see convergence of a lot of different component technologies in the market place right now, but I am not convinced yet that any one of them offers a complete solution.
“Technology requires a safety culture in order to be effective and that’s really where Newmont is concentrating on – making sure the technology is not a distraction to the processes and procedures that we have in place.”
Despite the debate about the effectiveness of the varying collision avoidance systems available, Bell said a mandate requiring Queensland miners to use at least one technology was imminent.
“Mines have different requirements in terms of what they want to do,” Bell said.
“We will just tell them this is what we want, these are the things that [are] available, we expect you to have something in place.”
However, he added that as the technology evolved, miners might be forced to use certain systems that proved more effective.
“It’s something we will look at,” Bell said.
“We may well set minimum standards, if you like.
“Proximity detection and collision avoidance systems are not a silver bullet to stop all these accidents but it will reduce the number of fatalities, there is no doubt about that.”
