December 2018

Mining automation: enhancing precision

  • By Professor Ross McAree, School of Mechanical and Mining Engineering, the University of Queensland

Following the huge interest and application of autonomous technology, industry case studies suggest that the true value of automation lies in its potential to deliver precise mining

There has been sustained interest over the last 20 years in the potential of autonomy in mining. Much has been promised and a good amount delivered. Autonomous haul trucks, for example, are now commercially available from the major manufacturers, as is technology to automate some other operations. Nevertheless, confusion exists about the value proposition of automation and, more generally, what problem (or problems) equipment automation really addresses.

Why automate?

The answer is self-evident: to increase operational efficiency. That is, the ratio of the output gained from an operation relative to the input needed to run the operation. Inputs include capital, operational expenditure and effort; outputs encompass revenue, product quality and quantity and growth.

I make this point firstly to emphasise that automation in mining is not an end in itself, but rather a means to optimise business processes. Secondly, this point reinforces the observation that operational efficiency involves both a numerator (outputs) and a denominator (inputs), and therefore efficiency is most effectively increased by raising the numerator and lowering the denominator simultaneously.

Current discussion too often focuses on inputs alone. It is too simple to argue that capital investment in automation technology reduces operation costs by reducing labour requirements. This misses the main opportunities presented by automation, and is otherwise unhelpful as it plays in to the debate over the negative impact of technology on work, jobs and wages – and even helps fuel fears of an impending robot apocalypse!

Historical precedent suggests such negative impacts are unfounded: real wages, the number of jobs and worker safety have increased throughout the industrialised world since the industrial revolution, including mining, because of technological innovation. 

A more constructive view is that technology is a lever that reduces the costs of production. In a competitive market, this leads to increased demand, which leads to increased production. This in turn requires more labour and delivers other consequential economic growth.

In this perspective, automation is just another technology and the mining sector is well versed in the use of technology to reduce the costs of production. 

So how does automation reduce production costs if not solely by reducing labour costs? Autonomy brings increased precision, and it is through precision that the mining industry reduces costs, increases production rates and improves product quality – all of which positively impact operational efficiency.

Precision mining

The word precision is distinctively appealing. It’s partly borrowed from Latin and partly from French, and in both languages its meaning is grounded in the idea of ‘separation’. The Oxford dictionary uses the phrase ‘with exactness’ among its definitions, and engineering and science graduates are well-schooled in the distinction between precision and its close cousin, accuracy, through experimental work. A set of experimental results that are in close agreement are said to be precise, whereas a measurement is accurate when it is close to its true value.

But precision has a broader use that seems to make it particularly apt in various circumstances or activities. Something done with military precision is done in a very organised and exact way. Precision medicine is medical care designed to optimise the therapeutic benefit for a specific group of patients. More examples abound: precision driving, precision flying, precision machining. They all evoke impressions of calm, carefully planned actions that are faithfully and methodically executed with exactness and meticulousness.

Precision mining should evoke a similar picture. It is therefore interesting that the phase seems rarely used, and never, so far as I can discern, with a deliberate purpose. By avoiding this term, we might be missing the opportunity to set down an important guiding principle for advancing mining practice. A philosophical cornerstone, if you like.

Contrast this with the manufacturing sector, where the quest to improve precision has been a celebrated driver of technological innovation and consequent economic growth for 250 years. This quest started with James Wilkinson’s development (circa 1774) of the boring machine, which, paired with James Watt’s invention of the condenser, made steam power economically viable and was the catalyst for the industrial revolution. 

Henry Maudslay’s invention (circa 1800) of machine tools meant that machines could make components of other machines repeatedly, with levels of precision that allowed standardisation of components (eg nuts and bolts) and interchangeable elements, easing the burdens of repair. Machine tools made machinery cheaper and more reliable, and significant economic growth followed.

One hundred years later, Henry Ford’s systemisation of assembly lines (circa 1908) enabled an enormous increase in the production of Model T Fords through reduction of manufacturing costs. Automobile production became more precise and transportation became affordable to the masses. We all became mobile and the economy boomed!

There is not sufficient space in this article to tell the full story of how precision enabled global economic growth through better manufacturing. In short, the manufactured goods of today, in all of their exactitude and functional capability, exist because sufficient manufacturing precision has been achieved to enable them to be produced at an acceptable cost.

The resources sector has been on a similar, but less celebrated, journey of ongoing improvements in precision that have delivered better yields at reduced cost. A case study by Schodde (2010)  estimated that in real terms, the delivered price of copper halved between 1900 and 2010 due to the combination of a better understanding of orebodies and continuous technological innovation. 

My contention is that the next step change in precision mining will come through automation. To achieve the benefits on offer, we should be unashamedly fixated on increasing the precision of mining processes.

Enhancing mining precision

Bruno Walter, the German pianist, composer and conductor, made the following observation about music that I think applies equally to mining, as well as other human endeavours:

‘By concentrating on precision, one arrives at technique, but by concentrating on technique one does not arrive at precision.’

The following case studies drawn from the University of Queensland (UQ) research program on automation illustrate how focusing on precision can help us improve technique.

Decisions made by operators in positioning and moving material during dragline operation are critical to production rates and effective spoil management. Dragline operation has a number of attributes, including the complexity resulting from the infinite ways in which the machine can be applied to an excavation task, and finding the best balance of the competing objectives of compliance to plan, maximising productivity and fitting spoil to the space available.

With funding from the Australian Coal Industry’s Research Program (ACARP), and in collaboration with Brisbane-based Mineware,  researchers at UQ have been wrestling with these challenges to develop and trial a prototype operator assist technology for dragline excavation sequencing (see Austin et al, 2018).

The technology provides guidance to operators on where to position the machine, where to dig material and where to place the dug material. This is a step towards eventual automation of draglines, but we think some benefits can be realised by a decision support tool that improves operator technique.

There are two main areas of opportunity for increasing the productive output of draglines. The first relates to achieving consistent operation at or near the maximum productive capability of the machine. Here we have found that productivity rates are surprising – about 40 per cent lower, on average, than they could be if operators pushed the machine to maximum capability.

There are many reasons dragline operators work conservatively. Most of these boil down to the complexity of effectively operating a dragline at full capacity for long periods, including coordinating hoist and drag at full swing without colliding the bucket into the spoil. 

A 40 per cent improvement opportunity is significant, and an automation system, with knowledge of terrain and a clear plan of where to dig from and where to spoil to, could routinely coordinate the machine’s motions with precision at maximum capability, allowing the opportunity to be realised. 

The second opportunity is improved task sequencing. This relates to questions such as where to position the machine, where to dig from and where to spoil to, so that the spoil fits the available space and the production rate is maximised. We have found a further ten per cent improvement to productivity is possible by optimising the excavation sequence.

Optimised excavation is the essence of precision mining, and while some of the benefit is realisable from the decision support tool we have developed, the opportunity is unlikely to be fully realised without automation. This is our next challenge.

We have found similar outcomes in other automation projects.

Work with Caterpillar, also funded by ACARP, has supported the development of autonomous dozers capable of strip mining using the ‘pivot push’ method.

Our focus has been to find the best way to choreograph the activities of dozers, along with supporting excavators, to maximise the rate of overburden movement. Again, the focus is on bringing precision to the task and this in turn reveals not only the right technique to use when pivot pushing, but also delivers a healthy productivity improvement.

In another project, UQ is working with Brisbane-based PlotLogic, supported by funding from the Minerals Research Institute of Western Australia (MRIWA), to identify ore waste boundaries for gold and iron ore at the point of excavation using hyperspectral imaging. This offers new precision in knowledge of the orebody and has the potential to incorporate accurate ore mapping into daily workflow, increase recovery, reduce dilution, enhance mining to plan and facilitate short-interval control.

The theme of precision pervades our thinking, and through a focus on precision we are finding insights into how to mine more effectively. Inevitably, we are also finding that automation is an essential prerequisite to realising value.

Beyond islands of automation

Islands of automation, which have been the focus of current research and commercialisation activity, deliver benefits through enhanced precision in task execution.

However, the precision mine of the future will not be realised only by small adjustments made independently at each of several margins. Rather, the truly precise mining operation will involve substantial and closely coordinated changes across a range of the enterprise’s activity.

The full benefits of this next level of precision might only be achieved by a radical repositioning of how we think about mining technology, so that individual components are interoperable and integrate at the enterprise level. This will allow mining activities to be carefully planned, fully coordinated, and methodically executed according to the plan. That’s precision mining.


Feature image: Midkhat Izmaylov/Shutterstock.com.

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