Product Code: ICA11_205

Real-Time Process Control by Machine Vision
Authors:
Christoph Franz, Fraunhofer ILT; Aachen Germany
Peter Abels, Fraunhofer ILT; Aachen Germany
Michael Merz, Fraunhofer ILT; Aachen Germany
Holger Singpiel, Silicon Software GmbH; Mannheim Germany
Johannes Trein, Silicon Software GmbH; Mannheim Germany
Presented at ICALEO 2011

Quality assurance in laser processing is often provided by post process inspections with machine vision solutions. When process stability gain is needed, one-dimensional signals like diodes or pyrometers which measure the emitted radiation of the laser process may be applied for closed-loop control of e.g. the laser power. Such signals mostly provide short latency and good signal to noise ratio, but represent only mean values of the whole processing area or parts of it. To overcome the lack of spatial resolution in closed loop control, this paper explains how real-time computer vision improves existing processes and enables new laser processes. Furthermore examples of machine vision algorithms are presented which measure geometric and kinematic properties of the process zone in real time. Examples include welding and SLM.