Easy field-applicable calibration of a miniaturized light sectioning sensor with application-specific illumination optics

According to the “VDI-Roadmap 2020”, flexibility and miniaturization are the two major challenges for production measurement technology in the next 5 years. Therefore, miniaturized optical sensors that can easily be adapted to each application will become more and more important in the future. One approach to fulfil this requirement for 3D sensors is to use application specific illumination optics for each inspection task. However, this is only feasible if there is an easy way to calibrate each new sensor setup – preferably also in the field. In this contribution, we demonstrate such a calibration procedure for a light sectioning sensor consisting of a line laser and a super-miniaturized “NanEye2D” camera manufactured by ams (size: 1.0 mm x 1.0 mm x 1.7 mm). As the camera is the only physical invariant in this setup – following an approach proposed by the OSMIN group of the University of Erlangen – it is used as a calibration tool for the whole sensor. This requires a very good photogrammetric calibration of the camera itself, which is especially challenging considering the extremely distorting imaging optics involved. A complete calibration is shown and quantitatively assessed