Manufacturing Metrology Team

Self-calibration for optical micro-CMM

A collaboration between the Manufacturing Metrology Team and the Department of Production Engineering, KTH Royal Institute of Technology, is carried out to develop high precision and accuracy calibration techniques for optical micro-CMMs. In the first stage of this project, a novel distortion correction method for 3D optical imaging systems has been developed based on the self-calibration technique and dedicated image processing method. Differing from the traditional distortion correction method where an expensive standard artefact is needed, an inexpensive metal surface, e.g. the surface of a coin, or a scratched and defected mirror, may be used in the new method and a precision of a few nanometres can be achieved over an area of a few mm.

Following Dr Peter Ekberg’s visit to Nottingham last November, Dr Rong Su visited KTH this March to make progress on this project. They continued the development of the image processing and self-calibration method for the lateral distortion correction of a coherence scanning interferometry (CSI) system. A manuscript is prepared for submission to a high impact journal, and the work will be presented at the ASPE topical meeting in Tucson, Arizona in April.

This work will lead to a completely new way of calibration of 3D optical imaging system and optical micro-CMM. Most of the laboratories and industries that are using these optical metrology instruments may be benefitted from this research in terms of the reduced calibration cost and increased accuracy.

Manufacturing Metrology Team

Room B38 Advanced Manufacturing Building
Jubilee Campus
Wollaton Road
Nottingham, NG8 1BB