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Recent years have seen dramatic expansion of the use of cobots in active production environments. Advancements in sensors and software have redefined the potential of human-machine collaboration, resulting in mechanical systems that can more easily cooperate with their human counterparts, while also ensuring a safe working environment.

As the technology has progressed, many companies have discovered ways to reap the benefits of modern cobots beyond manufacturing and assembly operations. At Gronbach, a global manufacturer of high-quality parts, assemblies and products, the company’s research and development team recently put KUKA Robotics’ LBR iisy cobot to a new task: product testing.

Gronbach was founded in 1964 as a hinge manufacturer. Six decades of steady growth and strategic diversification have resulted in the company operating five production facilities across Europe, opening a sales office in the U.S. and employing approximately 1,200 team members globally.

Over the years, Gronbach built a reputation for the development and production of technical assemblies and complete products of exceptional quality. Currently, the company serves over 500 customers, ranging from start-ups to multinational corporations, spanning sectors that include household appliances, gastronomy, medical, automotive and consumer goods.

One of Gronbach’s key competitive advantages can be found in the Austrian village of Niederndorf, at the foot of the Kaiser Mountains. Here, the company maintains a production and R&D site that houses an in-house team of experts responsible for research and customer-specific development of devices and assemblies. This department impacts all aspects of design and production, including mechanics, electrics, electronics, software and more.

With Gronbach’s team in Niederndorf having successfully completed hundreds of projects on behalf of its customers, the company decided to apply its expertise to developing products under its own branding. Key among these is the new LIGRE brand of high-end coffee machines, which recently launched a portfolio that includes the LIGRE siji coffee grinder.

During the design of the LIGRE siji, Gronbach embraced two key objectives. First, the coffee grinder was to include the ability to preset the amount of coffee to be ground within one gram, a feature that was entirely new to the consumer segment. Second, it must be able to maintain this level of precision over a full service life of ten years. Over that time period, it would be expected to grind approximately 500 kg, or half a metric ton, of coffee.

Once the Niederndorf R&D team had a design they believed capable of meeting these criteria and built a prototype, they needed an economically viable means to test it. Determining long-term performance under a variety of operating conditions would require both radical acceleration of the testing process, as well as extremely precise repeatability. The results needed to be incredibly reliable to validate the grinder’s operation and provide findings that could be incorporated into future product designs.

The R&D experts at Gronbach quickly came to an agreement that an automated robot solution was the only way to achieve cost-effective quality control using a test setup. The Niederndorf facility already had multiple industrial robots from KUKA Robotics in use, leading the team to evaluate whether KUKA offered an option that would work for their specific application. The LBR iisy cobot seemed to fit the bill.

Featuring six axes of motion, a 3-kg payload and 600-mm maximum reach, the LBR iisy provides ready-to-use automation out of the box. The cobot integrates intuitive features and an operating system that allow users of all skill levels to quickly and easily teach it to perform tasks with precision and repeatability. Additionally, despite its relatively low cost, the LBR iisy incorporates high-grade joint torque sensors in every axis, providing certified collision protection to ensure safe operation alongside employees.

“The cobot solution is an invaluable benefit for the necessary flexibility in a test laboratory,” said Peter Kopfensteiner, research and development, division appliances at Gronbach. “Other industrial robot solutions with complex safety structures were not an option owing to the high expense for a test series like ours, mainly because the costs were entirely disproportionate to the relatively short period of use.”

Once the R&D department acquired the LBR iisy, they quickly set it up and trained it to perform a series of steps. The cobot would initially move the siji’s portafilter to a precision scale to obtain a tare weight. It would then move it to the grinder and wait for the grinding process to be completed. From there, it moved it back to the scale and recorded the net weight of the amount of coffee ground. Lastly, it would empty the portafilter before starting the process anew.

KUKA Gronbach LBR iisy Cobot Bear Beitet

The Gronbach R&D team was particularly impressed with how easily the process was programmed once the cobot was in their testing lab. The LBR iisy features a Teach button that streamlines programming through human-robot interaction.

“You can guide the cobot manually to teach it the desired movements and waiting times,” explains Michael Reindl, account manager at KUKA Robotics. “It’s very easy, with just the press of a button. This allows for flexible application options and it can be commissioned and operated quickly and reliably, whether by automation experts or robotics beginners.”

Over the span of two months, the cobot performed this sequence 55,000 times, validating the performance of the design of the siji coffee grinder.

“Our aim was to test the grinder’s simulated service life to gain insights into wear and accuracy,” explained Dipl.-Wirt.-Ing. Alexander Fahringer, technical development and test engineer at Gronbach. “The grinder worked so well that it indicated practically no wear and tear after simulating ten years of use, so it would last for significantly longer.”

While the KUKA LBR iisy met and exceeded expectations testing the new product, Gronbach sees even more potential in the cobot’s future. For example, given that it was measuring ground coffee, this application used only a fraction of the LBR iisy’s maximum payload of 3 kg. Based on his team’s experience with the LBR iisy, Fahringer sees a future for cobots in development departments, such as in quality management.

“It’s good to know that there is more scope of other possible applications and processes,” he said. “As automation engineers, we are already thinking how the cobot will assist us with further quality controls and processes.”

In general, companies like Gronbach are starting to look beyond production and assembly for cobot integration, seeking out any simple, monotonous and repetitive tasks that take place in the vicinity of employees. Particular to the LBR iisy, KUKA offers variants with maximum payloads of 11 kg and 15 kg, both of which are dust- and splash-proof (protection class IP 54).

The use of cobots promises to eliminate workers being subjected to many tasks that are unpopular or even potentially harmful to their health. For product testing, they also offer the added possibility of even stricter quality management. In Gronbach’s case, each individual grinding and weighing cycle was logged continuously with absolute reliability, allowing any variance to be detected in real time.

Companies looking to evaluate how a cobot would perform in their specific application should ask suppliers about the potential of trial periods, which are increasingly being offered to help inform the purchasing decision process. For example, Reindl explained, “We are happy to provide customers with handy collaborative robots like the LBR iisy cobot to try out and test in their operations.”

As for the future of cobots for Gronbach’s R&D team, the LBR iisy alone offers incredible potential for the team going forward. After all, the recent project required just 55,000 test grinds, while the cobot offers several million cycles as standard.

“It’s only now just properly worn in,” joked Reindl.