Product Code: ICAL06_701

Applicable Sensor for a Multivariate Process Controller
Authors:
Andreas Otto, Chair of Manufacturing Technology - University of Erlangen-Nuremberg; Erlangen Germany
Simon Dietrich, Chair of Manufacturing Technology - University of Erlangen-Nuremberg; Erlangen Germany
Presented at ICALEO 2006

Laser materials processing is a modern joining technology often applied in the automotive industry. The process result is influenced by the user defined process parameters on the on hand and uncontrollable disturbance variables on the other. Nowadays the user defines process parameters located well inside the process window thus not fully exploiting the process possibilities. The reason for this is the missing ability of a fast and reliable multivariate process control. By a dynamic navigation this controller could achieve unused parts of the process windows bordered by the physical limits. Besides the need of fast data evaluation and process parameter adaptation an applicable sensor is an open challenge for the definition of named closed-loop control. In this contribution the authors will present the use of an "Optical Nozzle" as sensor for the closed-loop control of the laser materials processing. The controlled parameter in this approach is the distance between the laser optic and the process emission representing the material surface. From the optical signals of the "Optical Nozzle" an orthogonal distance value unaffected by variances in laser power and feed rate is calculated. The paper will demonstrate the suitability and application of the generated signal for the closed-loop control of the focus level.