Laser welding and brazing is being applied more frequently in high-volume car and truck manufacturing. Advantages include high production rates, easy automation, cost effectiveness, high quality welds, and low heat input. Although steel sheet is the most laser-welded/brazed material, laser welding is gaining acceptance in many applications, as lasers can weld a large range of materials thicknesses and types, including aluminum.

Increasing requirements for product quality and production rates demand laser welding production systems that are self-monitoring and adaptable to real world conditions.

Laser vision cameras are being used successfully in many high speed sheet processes, such as for tailor welded blanks and laser brazing of car roofs to find, track, and adapt to joint location and shape changes. Laser vision cameras, placed right behind the laser welding head, can perform real-time weld quality assessment. To complement seam tracking and weld inspection, a laser process control system (LPCS) – using coaxial monitoring of the thermal radiation from the weld pool area and back reflection of the laser beam from the work-piece – can be used to look inside the process to detect internal defects such as pinholes. Pages 58 and 59 discuss how to incorporate a LCPS into production.

Servo Robot Corp.

About the authors: Jeffrey Noruk is president of Servo Robot Corp. and can be reached at 262.613.2921 or Jean-Claude Fontaine is executive vice president at Servo Robot Corp. and can be reached at