Optical 3D position sensor for the fast tracking of light sources

Avoiding weld defects and ensuring a stable welding process in deep penetration laser welding requires that instabilities are kept at a low level. In this paper, a sensor is introduced that is designed to track the 3D position of the center of the process emissions and its fluctuations, which can be correlated to process instabilities. The sensor's resolution and operating range are discussed by means of an analytical model, and the experimental measurement principle and data evaluation method is demonstrated. It is concluded that investigations on the influence of size and shape of the measured light source on the calculated position of the center of the process emissions will further improve the performance of the sensor.