Micro-triangulation for high accuracy short range measurements of dynamic objects
Vasileios Vlachakis
1st PACMAN Workshop2 - 4 February 2015
CERN, Geneva, Switzerland
2
Outline
What we measure? Angles
What we can do with such observations? Geodetic Networks
How precise the system can be? Micrometres
Why μ-Triangulation and QDaedalus? Object Target Recognition
What this system can contribute to PACMAN? Fiducials + Wire
Are there any potential for improvement? Yes, as always!
Horizontal angles
Vertical angles
α
Minimum constraints - DoF
Y
Z
X
Position Orientation
Scale
ScaleRelative interferometer
Absolute interferometer
Scale bars
CMM
QDaedalus
• Developed at the Institute of Geodesy and Photogrammetry, ETH Zurich
• Consists of hardware and software developments
• Replaces eye piece with CCD camera, non destructively
• Object Target Recognition
Why QDaedalus in PACMAN?• Object Target Recognition (OTR)
• Can measure spheres
• Can measure circles
• Can possibly measure the stretched wire
How μ-Triangulation can contribute to PACMAN?• Can measure targets (fiducials) and the
stretched wire in a common coordinate system
Which are the main advantages?
Portable metrology solution
Automatic measurements
• Without observer, remote control, cheap targets
Massive measurements
Accurate measurements
• High precision instruments, targets and algorithms
• Without human error
Low cost
Software improvements
• Improve Graphical User Interface (GUI)
• Upgrade QDaedalus - LGC communication (input, output)
• Visualize network adjustment results
Leica Nova TS50
Hardware improvements• Control several instruments simultaneously
• Develop online, remote control
• Reduce cabling / increase precision and portability
Algorithms improvements• Enhance auto-focus functionality
• Implement automatic intensity adjustment
• Drive instrument through the image
• Improve points management
Stretched wire detection & measurement• Combine focusing techniques
• Determine which pixels depict the centre of the wire (image processing)
• Extract angle measurements
• Estimate the plane (surface) that passes through the wire and the instrument
• Reconstruct the wire as a section of these planes (surfaces)
• Calculate the precision of the measurement
• Compare results with FSI and CMM
Conclusion
Thank you!