Interface: ZF presents eWorX

Schweinfurt, on the premises of the construction company Riedel Bau, which has a fleet of over 200 vehicles. A MAN semi-trailer tractor with ZF decals arrives with the autonomously acting test tipper trailer in tow. Not a pure electric semi-trailer as such, as that simply would not have been available at the start of the project, according to test engineer André Ehrsam. But that has no bearing on the development of the system. The beating heart of the eWorX is essentially the eCube, which is connected to the vehicle’s CAN bus and the power electronics, a ZF control unit with the appropriate safety standards, and an application-specific software package.

The eCube accesses all the relevant data from the vehicle, particularly relating to the battery and energy management system – and also makes use of potential sensor data from the body. In parallel, the body builder does not require CAN bus-related expertise, and can continue to focus on the production of the body.

Later in the series, it is hoped that the eCube will provide the link between the vehicle’s battery and the ZF filter box (400 V / 50 Hz), possibly to operate refrigeration units or the ePTO modular electric auxiliary drive producing 20 to 120 kW. For now, in the absence of an electric tractor unit, ZF has fitted its own 17-kWh battery under the semi-trailer. The ePTO of the prototype is equipped with a 4-kW cooling system, complemented by a 40-kW electric motor and a hydraulic pump. All these components combine to produce an electric auxiliary drive. But ZF wants to do more than just electrify the auxiliary drive.

Other benefits add to the absence of local CO2 emissions – for instance the absence of noise emissions. After all, the tipper body filled with gravel can be raised and lowered with only a gentle hum. And, by choice, that can either be unimaginably slow and gentle up to the moment when the gravel starts to slide – or quick and immediate for the first meters, something that would otherwise waste time unnecessarily. These are key points for Riedel Bau Managing Director Stephan Kranig. He has already had experience in his company with an electrically powered concrete mixer, and is convinced that the trend towards green construction sites will continue. “The noise emissions are also a major issue for us. It means that earlier deliveries become possible with a quieter vehicle, with greater acceptance on the part of residents,” continues Kranig.

There is great interest, in particular, in the possibility of controlling the tipper semi-trailer on an app for smartphone or tablet. “We are already using equipment like this nationwide. Ideally, the driver stands directly beside the tipper semi-trailer, with one finger on the touchscreen,” explains Riedel Bau authorized signatory Martin Schlereth. It enables the operative to tip the gravel more precisely, saving labor, time and money in subsequently distributing the material around the site. It also provides for maximum safety – also thanks to its self-explanatory operation.

It is therefore possible to view the angle at which the semi-trailer is standing on terrain, and quite simply electronically lock tipping in an unsafe position or when the brake is released. ZF has also located 230-V and 400-V sockets for external equipment in front of the semi-trailer axles, which can also be activated by the app. According to Schlereth: “It means that we can then connect up compressors or high-pressure cleaning equipment, which will most certainly be useful in practice.”

ZF ultimately wants to supply the eWorX system to body builders in a matching subframe. After testing, the first eWorX solutions are planned to be production-ready after testing by the end of 2022. ZF hopes to roll out the entire product range by the end of 2023.