Home' Position : Position Apl May 2015 Contents Rio Tinto's Argyle diamond mine,
in WA, was discovered in 1975,
when one carat of diamond was
found on Termites Hill. Mining started
1985, and the Argyle Jubilee, the world's
largest pink diamond at 12.76 carats, was
discovered at this mine.
More than 812 million carats have
been produced since 1985.
The Argyle pit is about 2km long,
1km wide, and depth is 250-500m. This
is Rio Tinto's one and only block cave
underground mine, where currently all
productions come from underground.
The underground mine was developed
under the existing open pit, and the block
cave is expected to propagate through to
the open pit floor in early 2015.
UAV subsidence monitoring
The Argyle Underground Block Cave
has moved into a phase of mining
where the extraction of ore from the
underground operations is having a
significant effect on the existing open pit
surface. The open pit floor deformation,
or 'subsidence', is being monitored on
a regular basis for rate of movement
and size of change, utilising Unmanned
Aerial Vehicle (UAV) technology.
The chosen UAV platform for
the Argyle Project is the Aibotix X6
Hexacopter. Since its purchase in July
2014, surveying specialist Neil Vucak
has attained his remote controller's
pilot certification and completed the
requirement for the Civil Aviation
of Australia (CASA) licensing for an
operators certificate and developed site
procedures to ensure all operations are in
accordance with the CASA regulations.
The craft's strength is in its ability to be
deployed from the pit crest and fly below
the pilot position, into the inaccessible
depths of the pit at 100m below its take-
off point, to collect photographs vertically
and on a 45 degree pitch to define walls,
toes and the pit floor position.
So far it has conducted over 50
successful flights on a regular basis,
with the post-processing of around
3,000 photographs gathered per mission
completed using photogrammetry
software. From these, geo-referenced
3D models, pdf images and orthophotos
can be constructed and then exported to
mining software for geotechnical analysis
on the rate of change in the pit floor.
This is a great example of utilising the
latest technology for mapping solutions
to establish best practice and systems to
satisfy geotechnical monitoring of the
Argyle Block Cave operations progress.
Why the X6?
The Aibotix X6 Hexacopter features
new technology backed by Leica, so
the technology is in constant upgrade,
providing good support and access to
An important consideration is that it is
capable of flying negative heights from the
remote controller (operator), to descend
into the pit's lower benches.
Automated waypoint plan execution,
coming-home and auto-land functions
make it easier for pilots to fly, while the
gyro-stabilised camera provides more
The X6 only needs 3m x 3m take-off
and landing zones and can hover over
points of interest for more detailed
inspections. The multi-rotor set-up enables
it to return home on just four of its six
motors, and the carbon fibre housing
around the blades makes it much safer.
The team found it invaluable to have
Stan Shults from the manufacturer to
assist with on-site requirements for flight
plans, copter capabilities, camera setup
and data processing.
What to look out for
• Training and CASA certification was
a time consuming process, which
needs a lot of dedicated time -- and
a contract pilot is required until
certification is complete.
• Negative height flights may require an-
tenna move on the copter. Flight times
of 12min covered around 2.5km dis-
tance, at maximum 800m from remote
control position for safe battery usage.
• Similar radio frequency for other
equipment was used on site (e.g.
ground-probe radar, prism monitoring
communications and remote controlled
loaders in workshop), which may effect
copter or other equipment and requires
application for remote operated
equipment to be used on site.
• The Agisoft processing requires a
high-spec computer to be purchased,
complete processing time was around
10 hours once operators were fully
competent in its use. ■
UAV makes diamonds shine
Flying the Aibotix X6.
The copter and pilots: Neil Vucak
(in orange) and contractor pilot.
26 position April/May 2015
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