Industry 4.0 opens up a wide range of opportunities to manufacture customized mass products flexibly and economically. The Chairs of Brewing and Beverage Technology and Food Packaging Technology at the Technical University of Munich have therefore developed an innovative automation concept together with the Fraunhofer IGCV and industrial partners Krones, Beckhoff, ProLeiT, Siemens, Dekron, Yaskawa Europe and the Weihenstephan state brewery as well as infoteam Software. RoboFill 4.0, as the project is called, is a new, flexible and modular concept for the industrial provision of customized beverage bottles and containers for filling and beverage technology. The focus is on batch sizes ranging from small batches to one-offs. According to the project specifications, all system components were to be designed as cyber-physical system components - a core element of Industry 4.0 - that communicate continuously with each other and with higher-level systems using network and cloud technologies. This enables autonomous production control and also forms the basis for optimization processes in production technology, such as predictive maintenance.

Sealed special servo gripper for bottle handling

When the Zimmer Group 's gripper specialists were asked to take part in the Bavarian Research Foundation's project, they didn't think twice. Without further ado, the Rheinau-based company took part in the project. As the project work progressed, the complexity of the task became apparent: the list of challenges grew longer and longer the more the subject matter was dealt with, and the requirements of the partners also grew steadily during the first year of the project.

The development of a suitable gripper for handling a wide variety of glass bottles with robots proved to be very complex and time-consuming, as a wide range of issues had to be addressed and taken into account during implementation. These included force-controlled gripping, sealed components, the exclusive use of food-safe materials or lubricants (NSF-H1) and communication between the gripper and the robot controller. When handling the bottles, it also had to be ensured that no bottle could break in the event of an emergency stop or a power failure on the system. The development of special gripper jaws, which had to be able to safely handle all the envisaged bottle types from 0.33 l to 0.75 l on the bottle neck and also on the bottle belly, also presented the development team at the Zimmer Group with a major challenge.

It quickly became clear that only an electric gripper of the current generation, the GEH6000 series with servo drive, could be suitable for this task. However, this was only available as a prototype at the time and had not even been designed for many of the requirements mentioned. For example, it was extremely time-consuming to seal an electric and compactly designed large lifting gripper in such a way that it could be cleaned with caustic spray water when stationary or that there was no risk of failure due to a short circuit in the event of a bottle bursting. This was followed by several development loops in which the knowledge gained in tests on the component geometry and its coating process and the materials used for the various seals and wipers installed were implemented.

Development of a gripper control interface

The solution that eliminated the problem with communication with the robot controller can be described as a noteworthy innovation. Instead of setting up a second, parallel controller for the grippers operating with IO-Link, as is generally the case, a special gripper control interface (HMI) was developed and implemented in the robot controller. Erik Bauhaus, project manager and M-TB developer at the Zimmer Group, praised the excellent cooperation with the robot manufacturer Yaskawa in particular. This is also bearing fruit beyond the project: "By implementing the Zimmer HMI in the robot controller, it is now possible to control up to four electrically or pneumatically driven Zimmer grippers on many industrial robots," explains Bauhaus.