In SMEs in particular, it is clear that even the most promising technology has no chance if the implementation effort for new orders is too great. And nobody changes machinery, work processes and cultures that have evolved over decades that easily.

Nevertheless, not everything has to stay as it is. New technologies can be used in a targeted manner where they bring great benefits with little effort. An important trend here is partial automation: after careful examination, companies can optimize certain processes and work steps according to their own needs. The Fraunhofer IEM tackles these tasks by working with small and medium-sized companies to find individual solutions that enable them to meet current challenges: One of the most pressing problems alongside supply chain bottlenecks and trade crises is the acute shortage of skilled workers.

An example from the field of collaborative robotics shows how a manufacturer of welding assemblies is automating previously manual work and making its production more efficient as a result. At the same time, the company offers its skilled workers interesting development opportunities in the field of welding. The industrial partner of the Fraunhofer IEM develops customer-specific system fittings, assembly and welding modules as well as special fittings. As with many medium-sized companies, the introduction of automation solutions has not been attractive for the company to date due to low production volumes. What was missing were efficient solutions that could also be used economically for batch size 1. The first starting points in production were in the area of welding: The pipe-in-pipe welding technique in particular is very demanding. Skilled workers draw on many years of expert knowledge in order to control the welding process, which was previously purely manual.

The aim of the collaboration with the Fraunhofer Institute was to partially automate this welding process. The robot-based collaborative welding system was to automatically localize and precisely process seams to be welded. The welding system had to meet two basic requirements: Firstly, subsequent operation should be possible according to the low code principle, so that the skilled workers can manage without classic, manual programming. Secondly, they needed to be able to concentrate fully on monitoring the welding process. By making work easier on the one hand, they should be able to use their indispensable process knowledge even more effectively on the other.

Why a collaborative robot?

Especially in established production environments - such as at the Fraunhofer Institute's medium-sized project partner - many different systems coexist. The Cobot is perfect for this coexistence: It is relatively light and easy to handle and makes it possible to design smaller robot cells. Especially when space is tight, a cobot solution is usually the best choice.

There is also a technical advantage when setting up for new orders: At the touch of a button, the collaborative robot is in freedrive mode and can be guided by hand. Once the component has been placed, the skilled worker manually guides the robot to the position to be welded and gives it the work order. Freedrive mode enables fast and effective set-up without complicated programming.

Intelligent software and central PLC

The skilled worker should only have to set up the welding system and then concentrate exclusively on process monitoring. In particular, the start-up of the process must be monitored. Small adjustments to the process parameters may be necessary, which still requires a great deal of personal expertise. To free up the necessary capacities, the intelligence of the collaborative welding solution lies primarily in the software. All the necessary processes, such as the control of the digital welding machine, are mapped in the software. A central programmable logic controller controls all process sequences, synchronizes the subsystems and acts as an interface to higher-level information processing systems.

The user selects between different welding processes on a control panel and configures the welding process via a central, standardized user interface. The individual programming effort otherwise required for each workpiece and the necessary knowledge of the properties of the different system components such as welding machine, robot or additional axes is no longer necessary. The user simply selects the process configuration for the respective workpiece and adjusts the welding current, for example, if necessary. Thanks to the sensors installed in the tool head, weld seams for complex workpiece geometries can also be produced automatically. The system detects process or material-related deviations in the workpieces and automatically compensates for them.

Room portals extend the radius of action

The small, flexible cobots are playing an increasingly important role in fully automated production environments. One disadvantage, however, is their relatively small radius of action. The Fraunhofer IEM has therefore joined forces with Rose+Krieger, a supplier of components and system solutions for automation technology, to develop a three-axis spatial gantry for its cobot solutions that significantly extends the working range of cobots. Intelligent sensors and algorithms enable smooth communication between the robot and the room gantry. The result is synchronized movements of the gantry and cobot as well as easy adaptation of the system to changing application scenarios without time-consuming conversion and set-up work.

Dr. Christian Henke heads the Scientific Automation department at the Fraunhofer IEM in Paderborn.

© Fraunhofer IEM

The collaborative welding system enables companies to produce economically even with a high number of variants and small quantities. At the same time, it makes the job of a skilled worker much more exciting and attractive. In principle, the solution presented can also be transferred to other sectors. It brings benefits where manual processing of products or workpieces is not economical or where physical workloads need to be reduced. Examples include surface processing such as milling or force-sensitive polishing or handling processes such as stacking or sorting.

Of course, the introduction of automation solutions always involves a process of change for employees. Success factors here are, on the one hand, a curious, tech-savvy workforce. On the other hand, managers must be able to allay concerns and offer support and further training during the changeover to new working techniques and processes. It is important to show employees the opportunities: Those who previously welded suddenly find themselves operating a complex automation solution - and are presented with completely new career opportunities.