To obtain on-line information about the different processes in laser machining like cutting, welding and material removal, optical sensors are integrated in the working head of a high power CO₂ laser machining system. In order to detect the dynamic light or plasma intensity fluctuation during machining, these sensors provide the real-time signal of the vapor or plasma flame intensity in the wavelength spectrum of 200 nm to 1100 nm. Moreover, the real-time intensity of the laser power is measured in real-time with a pyroelectrical sensor. The aim is to analyze each process. With the knowledge of the specific characteristics of the process, a closed-loop control is set up. Distinguishing between continuous and pulsed processes, different control algorithms have been developed and tested. Thus, a control system based on micro-controller hardware and its theoretical background for failure detection and closed loop control is explained.

Date Published: 17 April 1995
PDF: 9 pages
Proc. SPIE 2375, Beam Control, Diagnostics, Standards, and Propagation, (17 April 1995); doi: 10.1117/12.206976

Published in SPIE Proceedings Vol. 2375:
Beam Control, Diagnostics, Standards, and Propagation
Lindsay W. Austin; Adolf Giesen; Daniel H. Leslie, Editor(s)