In accordance with customer requirements, asking now for a dimensional check
of assembled parts as opposed to check of single components, the GSI Quality Control
department has bought a new instrument, Cronos 3D Scanner, capable of performing
this check. It's a photo scanner equipped with a double camera which allows
to take snapshots more accurately as compared to Braccio Faro 3D,
the laser scanner used previously.
If on one hand the recent purchase has granted a quality improvement,
on the other it has allowed to simplify the work of the scanning operator,
reducing time and problems.
In fact, the scanning of large components, such as bonnets assembled through
Braccio Faro 3D, was a slow and complex operation, as it was impossible to move
either the machine or the bonnet, without losing the spatial reference.
Moreover, due to limited length of the machine, the part could be scanned
only partially and the operation had to be repeated for the different areas,
either by moving the part or the machine continuously. Consequently the second phase
of the work, which is a comparison of the scanned part with a 3D drawing
and the drawing up of a dimensional check report, had to be repeated
for each scanned area. In general a complete bonnet scanning required
from 4 hours to a whole working day.
On the contrary, to perform a scanning operation with new Cronos 3D Scanner,
it is sufficient to apply some markers, that is black circles on a white background,
on the surface of the part. Then the operator, guided by the machine through
a visual system viewed both on the PC screen and on the part to be scanned,
is able to understand whether he has to get closer or move away from the component,
placing himself at a certain distance to take a photo.
Whenever a photo is taken, the Optical RevEng software recognizes the markers applied
on the various areas of the component and numbers them, therefore allowing to move
the component being scanned and/or the scanner in a better scanning position
without alignment problems of the different images acquired, before a new snapshot
is taken. Once the component scanning is complete, and unnecessary details
have been deleted and a final global alignment of the various images has been performed,
it is possible to create a thick point cloud or a polygonal mesh having a high number
of triangles, to be exported for use in Geomagic software to compare the part
with a 3D model and to draw up a final report of the dimensional survey.
Thanks to the new Cronos 3D Scanner, GSI is now able to satisfy any customer request
in the automotive industry granting high-quality scanning.