intelligent measurement processes in 3d optical metrology
TRANSCRIPT
Intelligent Measurement Processes in
3D Optical Metrology:
Producing More Accurate Point Clouds
21st century = explosion in the ability to measure
Also true for metrology...
Measuring Systems - History
CERN
Technological Advances
Measuring Systems
Each experiment generating
terabytes of observation data!
Each experiment generating
terabytes of observation data!
Intelligent Measurement
• What is it?
– A way to improve the accuracy of
measurement by producing consistent
measurements from several observations.
– Acquisition model of the system is
integrated within the continuous measurement
process.
•Reading an ambient temperature of 60°C in a conference room…
•Reading a diameter of 100 mm for a coin…
Intelligence would lead to a
second measurement...at least...
Intelligence would lead to a
second measurement...at least...
3D Optical Metrology
• Metrology
– Inspect parts by extracting measured characteristics
from geometrical entities (circles, planes, etc.)
– Based on a limited number of calculated points
• Optical Sensors
– Produce a very large number of observations (20,000
to 1,000,000)
– This allows better definition of the surface
– This also allows local characterization of the error
Intelligent Measurement - Presentation
1. 3D Optical Metrology
2. Producing 3D Points
3. Acquisition & Calibration Model
4. Framework for Intelligent Measurements
5. Application of Intelligent Measurements
Observations to 3D Measurements
• Raw points = 3D point clouds from a sensor?
• Not raw observations…...They are the result of several calculations
– Example: CMMBasic observations are collected from the linear or angular encoders
Producing 3D Points - CMM
The 3D points are the result of
calculations from the parameters of
the acquisition model of the device.
Linear and
angular encoders
Observations to 3D Measurements
• In any measuring systems, all points are
calculated… Only the nature of those
calculations changes.
Producing 3D Points – Intelligent
Measurement
The 3D points are the result of
calculations from the parameters of
the acquisition model of the device.
CCD
2D subpixel
positions
Again...
Acquisition & Calibration Model for
Intelligent Measurement
Example: Impact of the angle of incidence
Framework for Intelligent
Measurements