Digital twin and low-code for clean railways

Thanks to digital twins, low-code, and automation, BHB worked with Mitsubishi Electric and ATINA to develop a resource-efficient tram washing system for Zurich—with significantly less effort.

Less effort for complex projects: Thanks to digital twins, low-code, and modern automation, BHB Waschanlagen, together with Mitsubishi Electric and ATINA, has implemented a particularly resource-efficient tram washing system for Zurich's public transport company—with significantly less time and expense.

The new rail washing facility operated by Verkehrsbetriebe Zürich in the Oerlikon district is special in several respects. Instead of the usual two, four individually movable washing cars are used here, which, thanks to automation technology from Mitsubishi Electric, enable particularly thorough cleaning results with short washing times and high energy efficiency. For the mechanical engineering company responsible for the project and Mitsubishi Electric customer BHB Waschanlagen Vertriebs GmbH, this challenging project also represents a milestone in its own digital transformation. This is because an innovative digital twin process was used here for the first time in combination with simplified low-code programming. This made it possible to plan the complex system with significantly less effort and to greatly reduce commissioning times. The 20-strong machine manufacturer team received support from Stuttgart-based engineering firm ATINA, an experienced software specialist from Mitsubishi Electric's partner network.

Low-code programming and digital twin

Increasing customer demands for flexible, networked, and resource-efficient systems—especially in times of skilled labor shortages—require new digital concepts, says BHB Managing Director Tobias Straub. “Through Mitsubishi Electric and its Automation Network, we came into contact with the engineering firm ATINA, which provided us with significant support in our digitization efforts,” reports Straub. “This enabled us to use a digital twin and the new low-code programming for the first time in the Zurich project.”

As a pure scripting language, the low-code programming developed by ATINA eliminates the need for hard-coded, line-by-line programming. Washing programs can be easily parameterized using an Excel spreadsheet, even without in-depth programming knowledge. This saves time, reduces sources of error, and facilitates subsequent revisions. With 200 lines of text instead of 4000, the programs are also clearer and easier for service personnel to understand. A simple CSV export allows the programs created in Excel to be transferred directly to the Mitsubishi control system.

In addition to the scripting language, BHB also used a digital twin for the first time for the project in Zurich. All mechanical and electrical components of the washing system are stored there as fully functional 3D models and can be controlled by a real Mitsubishi PLC. Since the programs can be tested very accurately at the desk, commissioning on site is greatly accelerated and virtually error-free – an enormous economic advantage for all involved, especially in more complex projects.

Innovation meets automation

However, digital twins and low-code programming alone would not have been enough to meet the high customer requirements. That is why the innovations at the software level are based on Mitsubishi Electric's tried-and-tested hardware. At the heart of the control system is the compact MELSEC PLC FX5U-64MR/DS. “Our hardware is not only exceptionally robust, but also backward compatible across generations,” explains Michael Brandecker, sales engineer at Mitsubishi Electric. “This enables machine builders such as BHB to offer their customers products in which components can be replaced even after many years without the need for costly reprogramming.”

In addition, drives from Mitsubishi Electric ensure efficiency during operation: Frequency converters from the FR-E800 series enable flexible motor control, which reduces energy and water consumption and thus contributes to economical and resource-saving operation of the plant.

Future-proof mechanical engineering

The BHB project serves as a shining example, particularly for medium-sized German mechanical engineering companies. Thanks to close cooperation between partners who work together seamlessly, the company's digital transformation was successfully driven forward at just the right time. BHB contributes its many years of experience in plant engineering, ATINA provides the software expertise, and Mitsubishi Electric contributes robust automation components.

The result is a tram washing system that meets increasing demands for sustainability, quality, and efficiency—while demonstrating how medium-sized mechanical engineering companies can remain competitive and attractive to skilled workers with the help of digital technologies.

Images: Mitsubishi Electric