Realization of a self-calibrating setup for in-process deformation measurement based on speckle photography
Measuring systems based on speckle photography can detect shifts down to the nanometer range, in particular with the aid of complex optical systems (for example microscope objectives).
The knowledge of the exact imaging scale as well the geometric distortion has a great influence on the quality of the obtained measuring results. Contrary to the previous strategy – a calibration at a tensile test stand – a laboratory set-up for a calibration under production conditions is to be designed as part of the project. For this purpose, it is provided to realize the displacements of the measuring surface with an existing linear piezo stage and to determine the position with an interferometric comparison measurement. In this way, the geometric distortion errors of the imaging system can also be determined by the known and homogeneous displacement of the measurement object.
Possible work steps
- Establishing of the request profile
- Development of a basic concept - especially with regard to use in the production environment
- Mechanical implementation with linear axis / piezo-stages and control
- Software implementation and realization of the self-calibration