Fraunhofer Institute for Production Systems and Design Technology
Safe Processes, Strong Results
When robots assemble side by side with humans and machine tools manufacture components with micrometer precision at high speeds, safety is not a secondary consideration – it is a prerequisite. In the automotive industry and among its suppliers, it has long been a decisive factor in protecting employees and ensuring process stability and product quality.
But how can safety remain guaranteed when production becomes increasingly networked, faster, and more complex? Researchers at the IWF at the Technische Universität Berlin are working on answers to this question. Their projects range from more robust protection systems to intelligent robotics and precise manufacturing processes. Their goal is clear: production facilities that function reliably and remain safe at all times.
Shop-floor hazards
he productivity of modern machine tools is increasing, and so are the demands on their safety. Risk analyses alone are no longer sufficient and must be supplemented by precisely assessable and resilient protective measures. A key issue is the impact resistance of protective devices. That is, their ability to safely retain workpieces or tool fragments in the event of a breakage. The standard tests conducted until now have been destructive and were based on empirical values. This process is expensive, time-consuming, and often inaccurate.
Protective devices are tested in the PTZ Berlin’s impact test laboratory.
These standard projectiles are used to experimentally investigate what happens when workpieces or fragments are ejected from the machine room.
This panel withstood the experiment.
The IWF has developed a new statistical approach that significantly improves the quality of these tests. The study is based on 105 impact tests on polycarbonate viewing panels. In these tests, standardized projectiles were accelerated at the test specimens. For the first time, the evaluation definitively describes the impact resistance as a statistically normally distributed variable with a mean value and variance. This allows for a more realistic assessment of material properties and test results.
This makes the evaluation of the protective effect significantly more reliable. It can contribute to adapting protective devices to increasing spindle speeds and
the more frequent use of slim tool extensions. Existing standards such as ISO 14120 are being critically reviewed against this background. The IWF researchers’ work is adapting the protective concepts of modern machine tools to real hazards in production. This helps to better protect people and machines.
Robots protecting people
In modern production environments, people and machines are working together more closely than ever. Collaborative robots, known as cobots, are a key technology in this context. They are flexible, easy to program, and safe to use in close proximity to people.
A real-world laboratory was set up at PTZ Berlin as part of the Regional Transformation Network Berlin-Brandenburg (ReTraNetz-BB) project, funded by the Federal Ministry for Economic Affairs and Energy. The laboratory simulates the assembly process of a hairpin stator for electric motors using cobots. Researchers from IWF and Fraunhofer IPK are testing new interaction concepts, adaptive controls, and AI-supported process strategies under real conditions. The objective is clear: to make human-machine collaboration safer and more productive.
Safe processes are essential
Process safety is a central aspect of systems engineering. In the automotive industry, production systems must keep pace with growing product diversity and ever shorter product life cycles. Robotics plays an important role here, allowing complex manufacturing and work steps to be automated. However, it reaches its limits when it comes to high-precision processes. The reason for this is the nonlinear stiffness behavior of many robot arms, which changes depending on their position and the force exerted on them.
Researchers at the IWF developed an AI-based compensation approach that effectively compensates for these fluctuations. A neural network models the stiffness behavior and automatically generates corrected tool paths. Tests with an industrial robot of the type FANUC M-900iB / 700 show that dimensional deviations can be reduced by up to 75 percent – from an original 2.4 millimeters to 0.6 millimeters. At the same time, the roundness of the molded components improved significantly. The results are clear: intelligent control systems increase precision and make processes more stable. This makes robots a tool that enhances quality and safety.
These types of tool extensions can become projectiles if they come loose during machining, posing a risk to people in the vicinity.
During slide burnishing, components are manufactured with the highest precision using a diamond head.
Safety as a product requirement
Not just the production process, but also the quality of the manufactured components are safety factors. In the automotive industry, there are strict requirements for the precision and surface quality of components. Life-threatening accidents can occur if crankshafts, bearing bores, or housings fail.
The diamond slide burnishing researched at the IWF offers a novel solution for manufacturing such components. A monocrystalline diamond head is pressed into the surface of a workpiece with a precisely defined process force and guided along a programmed path. This causes the top layer of material to be plastically deformed locally without removing any material. The surface roughness is reduced, while at the same time the wear resistance is increased by work hardening. The integration of the process directly into existing milling machines is a decisive advantage. It eliminates the need for additional machining steps, shortens the machining time, and reduces the use of resources. This results in components that are smoother, more precise, and more durable. This gain in safety extends to the end product.
Innovation driver instead of road block
Safety, precision, and reliability are not just prerequisites for modern production – they are drivers of innovation. The IWF’s research shows that safety is not just about protecting machines. It requires a systems approach that integrates people, technology, and processes.
Knowledge is being generated in all areas of industrial safety, from the development of protective systems to human-robot collaboration and the optimization of surfaces. This means that safety in the factory of the future is not an obstacle, but rather a driver of progress.