Complex control system with short cycle times

Bühler comprises two business pillars in order to optimally cover the two key areas of food and mobility on the market: Grains & Food solutions ensure safe and healthy food and animal feed, for example in grain processing for flour and animal feed, or in the production of chocolate and pasta. The Advanced Materials division contributes to the production of energy-efficient vehicles and buildings with solutions for glass coatings or the production of die-cast parts.

The Bühler die casting division is a significant player on the market. Around 50% of all structural components for cars are produced on Bühler die casting machines. In addition, around 25% of all die-cast products available worldwide are produced using Bühler technology. Or more than 1,000 foundries worldwide use die casting technology made by Bühler.

Short cycle times, open system architecture and text-based configuration

Bühler has been working with Keba for almost 30 years. When the company decided to no longer develop and manufacture IC control systems itself but to purchase them, a suitable supplier was determined in a selection process. Due to its good reputation on the market in terms of quality, the decision was made in favor of Keba.

The challenge for Keba was the speed and cycle times of the processes. One of the core processes is the control of the casting speed. This is a 3-stage electro-hydraulic control system in which the casting piston has to be accelerated from 0.5 m/s to over 7-10 m/s and decelerated back to 0.5 m/s within approx. 1 s. This requires particularly precise measuring cards on the one hand, and fast read/write cycles on the other. This requires particularly accurate measuring cards on the one hand, but also fast read and write cycles on the other, in order to ensure so-called disturbance rejection. Disturbance rejection enables a system to remain stable and accurate, even if it is affected by internal or external disturbances. It is therefore a core element for the robustness and adaptability of industrial control systems. Lukas Labhart, Team Manager Automation at Bühler Group: "At the time, Keba was the only manufacturer that could realize the fast cycle times required of a highly complex control system. We are talking about a response time of 200 microseconds." The competition at the time needed significantly more time.

The first system Bühler ordered was the K1 generation. Bühler is currently using controllers from the KeControl C5 series. Labhart explains: "This means that we have already used four generations of control systems - and have therefore been satisfied with the Keba solutions for quite a long time."

The system not only impressed with its short response time, but also with its high system performance. The overall system enabled Bühler to configure hardware and software much more efficiently. Labhart: "Keba already had a unique approach at that time: Keba's open system architecture and our goal of only offering automatically configurable systems were a perfect match". Bühler's die casting machines are basically series products, but they are adapted to customer requirements. This requires a flexible system for easy configuration of hardware and software. Text-based configuration was a must for Bühler. "We still benefit from this advantage today. The databases and mechanisms set up at that time characterize and simplify order processing and make the system very efficient. We have maximum flexibility and keep development costs low," says Labhart. Software can be created and customized at the touch of a button without developers having to intervene in the code. Options can be easily activated or deactivated.

Cooperation as a true partnership

Bühler describes the collaboration with Keba as a "true partnership". Labhart adds: "Our problems are also your problems and we tackle them together. The Keba team takes suggestions for improvement and requests seriously and incorporates them into the planning for future products." Keba's company size is also emphasized in this context. There are providers of automation solutions that are much larger. However, this does not only have advantages. "The size of Keba is pleasantly manageable - this, combined with the very flat hierarchies, means that we have quick and easy access to specialists, from which we benefit enormously". Short response times and the rapid development and provision of solutions are the result. "We also always have the same contacts. This inspires trust and means that they know and understand us, our needs and our processes very well," adds Labhart. The Keba style is "open, respectful and customer-focused".

In addition to the marketability of over-the-air solutions, the world of automation is currently very much focused on the topic of cyber security. "Together with Keba, we must and will master these challenges and be ready when the new Machinery Directive is adopted into legislation," says Labhart.