Real-Time Implementation of a Joint Tracking System in Robotic Laser Welding Based on Optical Camera

Robotic laser welding has been widely applied to industries due to its high flexibility and productivity. However, there are still some constrain such as heat induced deformation and inevitable fixture errors, which can affect the laser beam positioning to deviate from joint center, and that will lead to poor welding quality. In order to ensure high quality welding, a joint tracking system is needed to track the joint center in real time to keep the focus of laser beam following the weld joint consistently. This paper introduces laser welding, describes composition of a real-time joint tracking system which mainly includes image acquisition part, image process and analysis part, and motion control part, reviews relevant investigations of joint tracking system and algorithm. Although there are successful applications in real-time joint tracking, the systems and algorithms can only be used in limited situations. So, future research can be focused on problems such as the promotion of system performance, the commercial solutions for joint tracking, etc.