Applied Thermal Sciences, Inc is developing and validating an automated, large-scale laser-welding process that can be utilized to fabricate high-precision lightweight structural shapes for shipbuilding and other industries. Current industry practice is to purchase and then deflange or split structural, hot-rolled I-beams in order to create the required structural shape. Fabrication of structural shapes with an automated laser welding process allows the industry to utilize parts that are cost effective and optimally designed, reducing material waste during manufacture, enabling higher tolerancing of parts, enabling the use of newer higher yield strength materials, and reducing final product weight.
At the heart of this laser welding process is a real-time, adaptive process control system that fully integrates process parameter controls, active seam tracking, and online weld quality monitoring. This integrated control system has sufficient bandwidth and response time for welding speeds up to 600 inches/minute. It also provides the operator with seamless communications and the capability to monitor and control all subsystems from a single user-friendly screen. This paper describes the laser welding process control system and the fully integrated prototype facility, built to demonstrate and test this approach using a 25 kW CO2 laser.