The primary hurdle in programming of laser welding’s motion systems lies in the alignment of laser beam with the seams to achieve a high-quality weld. Traditionally, achieving such weld joints necessitated the programmer to manually set numerous points along the seam—a time consuming process. In response to this challenge, our project introduces a real-time seam tracking system. This system is adept at sensing and generating the optimal welding path in real-time, concurrently guiding the robotic system accordingly. A camera captures online images, and a processing algorithm analyzes these images to accurately indicate the welding path.
Research Highlights
- The intricate nature of edge or but laser welding poses challenges for achieving ideal welds due to high programing time required generating welding path manually.
- An online path-generation process for laser welding was developed utilizing image processing tools. This closed-loop adaptive controller enables optimized welding along the entire seam length.
Challenges
Laser welding, specifically in edge or butt seam joining, introduces a formidable challenge—precisely aligning the laser beam with seams to achieve high-quality welds with desired properties. The significance of this alignment cannot be overstated, as it plays a pivotal role in ensuring the overall integrity and efficacy of the welding process. Traditionally, operators must manually indicate numerous points and meticulously program the motion system to guide the laser along the seam, an inherently time-consuming process. Recognizing this inefficiency, a revolutionary real-time seam-tracking methodology was stablished by our team. This innovation aims to automate and expedite the seam-following process, significantly reducing the time investment required for precise seam alignment.
To achieve this goal, a monitoring system must be designed for acquiring real-time images. This visual data is then subjected to analysis by a sophisticated processing algorithm characterized by low time cost. The primary objective of this integration is to precisely generate the welding path in real-time. A further complication in the realm of laser welding arises from the inherent difficulty of detecting narrow edges, a challenge not commonly addressed in similar projects. By doing so, the project strives to expedite the inherent complexities of seam alignment in laser welding, laying the foundation for flawless weld joints that not only meet but surpass the desired properties. Beyond laser with seam alignment, the system should establish a robust solution that ensures proper sealing and effectively mitigates manufacturing defects, ultimately enhancing the overall efficacy of laser welding processes.
Our Solution
Developing a Laser Welding Seam Tracking system integrated high-speed cameras, image processing, and signal processing algorithms to enable real-time tracking and path generation for a robotic laser welding cell. A control logic was created to synchronize the laser welding motion precisely with the seam position. The seam tracking monitoring setup is shown in Figure 2-A. To provide an intuitive operator interface, a custom Graphical User Interface (GUI) for real-time monitoring and control of the system was designed as demonstrated in Figure 2-B.
Mentioning one of its applications, Figure 3 shows a heat exchanger on average has thousands of meters weld joints, connecting each disc to the adjacent one in edge welding configuration. As demonstrated in Figure 3, the current seam tracking system was used for laser welding of these sheets.
By implementing a diverse range of technologies, production time and costs for the welds were reduced by 70% using the novel seam tracking system equipped with laser welding.
Outcomes
- This novel seam tracking system reduced the programing time, operating costs, and manufacturing defects of the laser welding process.
- The current seam tracking system enhanced the weld quality and precision of laser welds in edge and but configuration dramatically.
- Seam-tracking technology was implemented for the laser welding of thin heat exchanger plates as a real application of this method.