JEC COMPOSITES MAGAZINE - Issue #129 - July/August 2019 - 22

MANUFACTURlNG NDT

Dynamic referencing

Portable metrology solutions enable more reliable and efficient measurements, and better
quality controls at each stage of the production process

Extendable measurement volume

Combination of contact
and non-contact
measurements

being portable, optical metrology provides
a measurement accuracy that is insensitive
to the instabilities of the environment.
Therefore, the measurement setup does
not have to be rigid and the measurement
volume can be wider than with standard
portable CMMs and even be extended
during the measurement.
Combining contact and
non-contact measurements
A portable CMM can easily integrate both
probing (contact measurements) and 3D
scanning (non-contact measurements).
Thus, benefits can be found from the ease
and speed of probing when only specific
measurements - fixture adjustments, critical features inspection, etc. - are needed
and, at the same time, from the amount of
data that can generate a 3D scanner when
a complete part inspection - FAI, PPAP,
distortion analysis, etc. - is required.
Dynamic referencing
Vibrations are common on a production

floor. They can come from nearby road
and rail traffic, production and handling
equipment, or operator manipulations.
Since quality control equipment is accurate
at the micron scale, these vibrations will
impact the measurement system unless an
optical CMM is used. Optical technology
systems, made of an optical tracker and
reflectors, deliver dynamic referencing by
optically tracking the measured part and the
measuring device at the same time. Optical
reflectors are used to create a reference
system that is locked to the part itself, so
the object can move during the probing
and scanning sessions. Thus, the measuring
system provides the same level of accuracy
regardless of the environmental instabilities,
user experience level, and setup rigidity.
Extendable measurement volume
While traditional CMMs have a measurement area mechanically limited to their
work table, articulated arms have a definite
measurement volume limited to the maximum attainable point. Optical portable

jec composites magazine / N°129 July - August 2019

CMMs, however, provide an extendable
measurement volume that does not require
any additional alignment or manipulation.
As long as the optical tracker sees its targets,
the measurement system can be moved. In
a context where composite materials often
mean large parts that must often be moved
around, having a flexible measurement volume that can be easily and dynamically extended without loss in accuracy or conventional leapfrogs is an important feature for
the operators. Finally, a wireless measuring
probe that can be freely manipulated by the
operators, without any physical attachment
to a poly-articulated arm, tripod or fixture,
is another feature facilitating quality control
at each step of the production process.
Results
Optical metrology, therefore, is intended to
simplify the measurement and quality inspection of composite parts. At each stage of
the production process, this portable technology enables more reliable and efficient
measurements, and better quality control.
Since it enables measuring the parts directly
on the production floor without a limited
measurement volume, less alignments and
manipulations are required, leading to less

JEC COMPOSITES MAGAZINE - Issue #129 - July/August 2019

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #129 - July/August 2019