Study on a new method of seam tracking and error compensation for tailored blank laser welding based on coaxial visual system

Tailored blank laser welding is one of the most famous laser joining application which plays an important role in the advanced welding. Tailored blank laser welding is widely used in automotive industry, shipbuilding, aerospace industry, etc. In tailored blank laser welding, the industrial robot that follows a preprogrammed path assisted with clamping equipment is often not able to guarantee a sufficient weld seam quality. Therefore, a seam tracking system is needed to improve the reliability of the seam quality. Error compensation is important for seam tracking in laser welding. The affecting factors on accuracy of robotic laser welding are analyzed especially the robot track error. A new error compensation method is proposed based on coaxial visual system which is used to obtain the guide laser spot for compensating the robot track error directly. Assisted with seam tracking system during welding process, error in the robotic laser welding could be compensated conveniently by this new method.