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!