autonomous haulage systems (AHS)
is the logical next step in the
evolution from fleet management
systems to true fleet automation
solutions.
What is autonomy?
At the most basic level, there are
four types and levels of autonomy.
David Goddard, portfolio manager
at Leica Geosystems, defines them as
follows:
n
n
Remote control systems
require human operators for
most machine functions but do
not require the operator to be
onboard. A line-of-sight view
of the equipment is needed,
however.
n
n
Auto-pilot systems
relieve
operators of some of the tedious
or demanding tasks on selected
road segments, but require the
operator to remain onboard.
n
n
Semi-autonomous and
tele‑operated systems
allow
operators to work from a remote
location, while automating
portions of the work cycle.
n
n
Fully autonomous systems
entirely eliminate the need for
human machine operators.
Essentially, then, AHS can be
defined as operating a haul truck in
a mining environment without a
driver. Depending on the design of
the vehicle, companies, such as
Autonomous Solutions Inc. (ASI), an
OEM-agnostic autonomous solutions
vendor, can accomplish this in a
variety of ways. “Many of the
mining vehicles we work with are
controlled electronically, so we tap
into the electronic system of the
vehicle (CAN Bus),” says
Dru Brown, marketing manager
at ASI.
Why autonomy?
Technology initiatives in mining are
usually driven by a business desire
to increase safety and productivity
and/or reduce costs. The
development of AHS is no exception.
Across the board with all OEM/OTMs
that were interviewed, there was a
consensus that safety, cost and
productivity are the primary drivers.
Secondary advantages include
increased reliability (machine
operates according to OEM
specifications, thus decreasing
unplanned maintenance) and
consistency (human resource issues;
labour cost fluctuation reduction).
Increased safety in AHS comes
from many different areas,
including:
n
n
A reduction of manpower
requirements in high altitude or
hazardous environments.
n
n
Removal of the human factor,
such as the risk of fatigue
from equipment operation
or environmental factors.
For example, the Yanacocha
mine in Peru operates at
4700 m (15,429 ft). As the ILO
Encyclopedia of Occupational
Health & Safety notes, at
altitudes of >4500 m (14,764 ft)
“maximal work capacity is
decreased, as people grow
fatigued more rapidly. Mental
efficiency is reduced and many
people find it is much more
difficult to concentrate.”
n
n
Decreased number of workers
around equipment with large
blind spots.
In both semi and fully‑autonomous
haulage, productivity gains should
be expected through increased
equipment utilisation with operation
through shift change, lunch and
bathroom breaks (about a 4 – 8%
increase) and sick days. In her
mining engineering Ph.D thesis,
1
Julian Parreira concluded that: “the
results show that an AHS is able to
increase either production or
productivity by 21.3%, due to
increased utilisation.” To put that in
perspective and using a very simple
extrapolated calculation, one of
Barrick Gold’s smaller minesites,
Ruby Hill, produced 91,000 oz of
gold in 2013. Assuming that there is
capacity downstream, using the
same strip ratio and average grade, a
production increase of 21.3% would
generate an additional 19,383 oz at
an all-in sustaining cost of US$ 887.
Using a gold price of USD$ 1200/oz,
the extra ounces would net an
additional US$ 6.07 million.
On the economics behind
autonomy, Parreira notes: “an
economic assessment of an AHS vs a
manual fleet shows an after-tax
incremental discounted cash flow
rate of return of 48.7% in comparing
a 7-truck AHS fleet with a 9-truck
manual system, both of which were
designed to achieve equivalent
production”. Cost savings can be
attributed primarily to maximising
fuel economy and minimising
maintenance costs.
Terry Vance, mining technology
solutions manager at Caterpillar,
summarises the benefits of AHS as
reducing “variability in the mining
process. Automated trucks perform
assigned tasks with precision, do not
need to stop for breaks or shift
changes, and fuel at the appropriate
intervals. The mine plan is executed
as designed and the automated
trucks can follow a planned,
predictable maintenance
schedule through enhanced
health monitoring.”
Current autonomous
initiatives
AHS initiatives, including pilot
projects or production deployments,
have proliferated worldwide within
the past five years. Rio Tinto, a
pioneer when it comes to AHS,
started trials with Komatsu in
2008 and has a reported 10%
improvement in time efficiency since
then. “The autonomous haul trucks,
which include 19 930E Komatsu
units currently working on two
mining operations, are considered a
vital component in the mining
company’s strategy of using new
technologies to increase efficiency,
reduce costs, and improve health,
safety and environmental
performance,” the mining company
said in a press release. In 2011,
Komatsu and Rio Tinto announced
that they had signed a memorandum
of understanding to take the next
steps towards building a fleet of
150 AHS trucks by the end of 2015 in
22
|
World Coal
|
September 2014
