Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Design of highly dynamic sensor and control systems for adaptive laser processing



Datum: 15.12.2003


Author


Reporter

  • Prof. Dr.-Ing. Dr.-Ing. E.h. mult. Dr.h.c. M. Geiger
  • Prof. Dr.-Ing. R. Lerch

Intelligent beam tools liberate their users from the necessity of precise process planing and from having to know the process window of the application. Utilising closed-loop control, they prevent inadmissible process fluctuations and a faulty process control with static, a priori fixed actuator positions. To equip lasers with the attractive properties of intelligent beam tools, an automated, timely and locally adjusted energy deposition is required. This work illustrates a path to this objective. It then concentrates on the resulting main questions of sensor-based determination of the energy density applied to the laser treated object and the density?s manipulation by actuators. Since the influence or effectiveness of actuators can rapidly vary due to the process state and accompanying disturbing effects, numerical procedures for sensor-based determination of unknown varying control path dynamics are developed. An example illustrates the use of the presented (real-time) numerics for control purposes. The numerics allow for the execution of several adaptive closed-loop control circuits on cost-effective PC hardware in parallel and each with speeds in the multi-kHz range. The axial distance measurement plays a key role in determining energy density. Several new techniques with attractive features are introduced and evaluated. To gain relevance for industrial application, all presented techniques were designed under the premiss of robustness and low system complexity.