Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Process-control with laser-beam micro-welding

Datum: 15.02.2002



  • Prof. Dr.-Ing. M. Geiger
  • Prof. Dr.-Ing. G. Sepold, Universität Bremen

Within industrially employed production systems for mechanical or electrical joints of high precision, flash-lamp pumped Nd:YAG solid-state lasersystems have been the technological basis for several years now. Objective of the entire investigation was to accomplish ready-to-use tools which help to enhance the technical capacity of industrial micro-welding devices on the one hand along with the desired welding quality on the other. Special attention was paid on proceeding in a stepwise manner and therefore help to better understand the evolution of the single modules of the control-system. Besides the specification of a newly designed multi-sensor welding head for the purpose of process diagnosis, basic research on micro welded overlap-joints represent the starting point of the successful correlation between certain input-parameters and the output of previously selected process sensors. By the combination of multiple sensors at a time and with the help of signal-processing-modules based on neural networks and fuzzy-sets, robust tools for monitoring and control of the micro welding process were achieved. In addition, online signal-processing methods were presented, which offer the capability of continuously help to minimize the weld defect-rate or permanently assure a sufficient weld penetration depth at overlap-joints.