TWI Industrial Member Report Summary 543/1996
K R Ayres
Joint tracking systems will see increasing application in laser welding as on-line monitoring and control equipment becomes more readily available.
Due to the relatively low tolerance of laser welding to joint misalignment and gap, joint tracking systems offer the potential for improved quality assurance by allowing adjustment for small variations in joint position and fit-up brought about by standard engineering parts tolerances. Joint tracking systems for laser welding applications usually need to locate the joint to between 0.1mm for 1mm thick sheet and 0.4mm for 6mm thick plate. In addition, the joint tracking systems need to be able to operate at welding speeds of between 1-10 m/min for typical plate and sheet applications.
To review methods for joint tracking with particular relevance to laser welding and to define outline system specifications for a number of laser welding applications.
The generic differences between laser and arc welding, see the Table, result in the need for different joint tracking system specifications for laser welding. There are five types of sensor which are generally used for joint tracking.