Vision Guided Robotics for Safe Metal Handling

Introduction

Material handling in the metals industry is a lengthy yet crucial process. As the competition and market demand go through rapid changes, manufacturers are under pressure to ensure product quality and increase product value.

Steel mills rely on affixing information tags to track and trace the product as it moves throughout the forming process. For decades, mill operators manually attached tags to the hot steel by welding or using a nail gun, a process that was both dangerous and prone to human error. On the other hand, mills that did not employ a tagging system painted or indented coded product information to the product ends. Often an OCR system was installed to read the product information. However, the system was costly and required consistent lighting, which can be challenging to maintain in a steel mill. Lastly, some methods only allowed for a limited amount of trackable information.

System Requirements

The manufacturers were looking for a solution to automate the tagging process with robotic arms. The employed 3D machine vision would scan the metal billets on the cooling bed to determine whether a tag was present. If not, the robotic arm would fetch a QR code tag from a tag dispenser and weld it according to the 3D scan result. QR code stores more information, while 3D scanning identifies the optimal welding area on the metal bar’s ends.

Additionally, the system needed to withstand a working temperature of 430°C/800°F with minimal supervision as the heat level is dangerous for human operations. The robots would be equipped with a collision avoidance sensor to prevent crashes with unexpected intrusions.

Billet tagging system diagram

System Description

Hermary’s SL-1880 was chosen to provide 3D vision to the robotic billet tagging application. The robot welds identification tags directly to the hot steel billets at 430°C/800°F. The billet tags contain all necessary information used for tracking the billet through the manufacturing process. Tags are applied to the billets’ ends, where suitable locations for affixing are identified based on the scanner’s scan data. Lastly, a vortex cooler was installed to prevent the system from overheating.

The Conclusion

The dangerous and error-prone task was eliminated, with the operators now providing onsite supervision of the system. It not only automates a repetitive task, but the system has helped improve workplace safety, streamlined production and significantly eliminated information errors.

“Automated Hot Steel Tagging will become the new standard for the steel industry.”

– Tim Dykstra, Concept Systems Inc.