Robot brings flexibility to laser welding

High-tech rooted in experience and innovation

One of the most advanced and flexible laser welding cells in Europe can be found at Innova in Laitila (Finland). KUKA Roboter GmbH, its system partner Kine Robot Solutions, and the Innova Adult Education Center pooled their experience and know-how to create the high-tech laser cell “Innova Lasepro”. The KUKA robots can work individually, with positioning tables or as a team, enabling extremely large parts to be processed. Be it laser welding, laser cutting or laser hybrid welding, all processes are camera-monitored.

Innova was founded in 1998 as an institute of further education, and is run by the Municipality of Rauma/Laitila. Its wide-ranging seminar program is aimed at working adults who wish to gain further qualifications. Around 650 students study at the Rauma and Laitila sites. Approximately 50 percent are sent by their employers. Courses are offered in subjects such as kitchen management, social welfare and health care, construction, and automation and metal engineering. This last subject is taught at the Laitila site. The engineering students here can benefit from state-of-the-art technology, for example in the field of laser welding. “We see ourselves as an institute of further education,” explains Anu Vuorio, Project Assistant for Laser Technology. “Our robotic welding cell, for example, is a project that was partly financed with EU subsidies, because it is innovative and probably unique within Europe.”

Many companies have the processing of their components tested on this system. In this way, Innova receives research assignments from a wide range of industries - especially the naval construction industry. “In this case, the components are often very large and bulky,” explains Juho Isotalus, Project Manager for Laser Technology. “They wouldn’t even fit on any other system.” But what is so new, unique and different about this cell? “Its versatility,” explains Jyrki Vilo from Kine Robot Solutions. It can be used for laser welding, laser cutting and laser hybrid welding.

Sophisticated technology A KUKA KR 30 HA robot is mounted upside down on a KUKA linear unit, giving it a travel of ten meters. Both the linear unit and the robot are special designs that have been optimized by KUKA for maximum accuracy. The KR 30 HA - HA stands for “High Accuracy” - is designed for high-precision tasks and is particularly suitable for laser applications or for measuring components. “Linear axes normally bend under the weight of the robot,” explains Peter Gmeiner, Key Technology Manager at KUKA Roboter, “and that affects the accuracy of the weld seam.” The longer the axis, the greater the deviation. Not so with this special design. The robot and linear unit achieve an accuracy of plus or minus 0.20 mm. “That is negligibly small,” says Juho Isotalus, who works every day with the Innova Lasepro cell.

KUKA robots as team partners

One KUKA robot - of type KR 210 - is responsible for handling the components and it is able to work together with the KR 30 HA as a team. This is done using a technology called KUKA RoboTeam, which enables robots to cooperate in real time on the basis of data exchange. Inflexible control blocks are consciously avoided here; instead, intelligently networked autonomous standard controllers are used, which can be freely combined to form an optimal cooperating group of robots for any manufacturing concept. The controllers of the individual robots can be grouped in any configuration.

The KUKA handling robot deftly manipulates the workpiece, while the welding is expertly carried out by its “colleague” suspended upside down from the ceiling. In this way, parts can be successfully welded or cutted in even the most inaccessible places.