45March 2016
device that allows operators to sort waste with-
out touching it, thus taking employees out of a
‘smelly, dusty and potentially dangerous envi-
ronment’.
One such unit has been in operation at a mate-
rial recovery facility in Amiens, France, since
September 2013. The process is based on a
vision system that provides an image displayed
on a touchscreen on which ‘intruders’ from a
predominant waste stream can be selected.
People vs. machine?
‘Air nozzles eject selected objects automati-
cally,’ Maitrot explained. A line-scan camera
with a specific lighting system was designed
in order to ensure a ‘realistic’ visual rendering
of the infeed. The material is treated according
to Veolia’s patented sequential adaptive loop
technology (SALTO), enabling the sorting of
different streams on a single conveyor.
So what makes I-SORT3R special? For one
thing, it differs from other sorting solutions
such as near-infrared spectroscopy and multi-
sensory technologies by virtue of the fact that
it only has automated extraction. ‘This means it
preserves the human ability to recognise objects
that other sensors did not pick up on, restor-
ing people as the missing link in the chain of
quality control,’ said Maitrot. She labelled this
a ‘human-machine interface’.
At the facility in Amiens, an image of the mate-
rials is displayed on the touchscreen monitor
for four seconds. Veolia opted for static images
instead of a video stream as this allows for more
freedom of spatial organisation. The duration
was determined in relation to conveyor speed,
width, length and material throughput. ‘Each
image represents a portion of the belt,’ Maitrot
noted.
She continued: ‘In our project, the customised
lighting system ensures that transparent plastics
are seen as such, not black – which is, of course,
the colour of the belt underneath. We experi-
mented to get the visual rendering just right,
not underexposed or overexposed. The colour
saturation displays the material purity.’
Picking precision
‘An image processing algorithm is imbedded
in I-SORT3R software,’ she told delegates. It
handles object segmentation plus detection of
isolated and overlapping objects. The system
‘Remotely operated sorting is opening the
way to a new generation of sorting centres.’
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