With the electric test truck named “Eddy”, Knorr-Bremse is making steady progress on the road to e-mobility. At the wheel is the eCUBATOR team, made up of international specialists from Munich and Budapest. Here they report on the latest successful eCUBATOR test series and tell us what added value the eVMC (Electric Vehicle Motion Control) software package brings to electric trucks and therefore to customers.
In the summer of 2022, a new electric truck with a slick black paint job arrived at Knorr-Bremse in Budapest. The eCUBATOR team had a clear purpose for the right-hand drive truck from England: the neutral test vehicle, since christened “Eddy”, should play a key role in the continued development of Knorr-Bremse’s e-mobility portfolio.
The eCUBATOR unit is the central hub at Knorr-Bremse for all e-mobility topics in the Commercial Vehicle Systems division. Development teams in Munich and Budapest are working on intelligent solutions – from traction, braking and steering to energy supply – using a holistic systems approach. “We are currently focusing on second-generation electric vehicles, which are expected to be on the market from 2025. Our first series of tests on the eVMC software package is also geared towards this generation,” explains Martin Mederer, Product Line Owner “Brake Control” in the eCUBATOR unit.
First of all, the electric truck was equipped with innovative Knorr-Bremse technology, in line with ideal test vehicle requirements. This work was performed at the Knorr-Bremse prototype workshop in Budapest and at the test track in Zalaegerszeg. The responsible design engineer György Surek recalls: “Among other things, we retrofitted the truck with high-quality measuring systems for data logging, two braking systems (EBS5, GSBC), various driver assistance systems (ABS, ATC, ESP) and a fifth wheel coupling for additional trailer operation. The mechanical modifications were then carried out by a specialist company in Budapest in accordance with all road safety regulations.”
Why is the eVMC software package one of the prioritized projects in the test series? Within the modular system of Global Scalable Brake Control (GSBC), eVMC is designed to recover as much energy as possible via recuperation and to further enhance safety functions such as ABS and ESP.
The test vehicle “Eddy” embodies the transformation of Knorr-Bremse’s products to e-mobility across all product groups in the CVS division. Eddy’s length of 10 meters, height of 3.50 meters and weight of 15 metric tons are spread over a beautifully crafted body made of high-strength steel with a black paint finish. The electric truck packs quite a punch, with 300 kW batteries and 200 kW power during operation.
Between June and October 2023, the eCUBATOR team carried out the eVMC test series on the state-of-the-art, fully equipped ZalaZONE test track in Zalaegerszeg, Hungary.
How do such tests work in practice? Knorr-Bremse has worked meticulously on its test cases, which are often based on legal regulations, over the past 20 years and integrated the latest requirements for electric drives. “We prepare the collected test cases for our series down to the last detail,” reports Surek. “We develop new software and compile EEPROM parameters, which are data required for operation, for further applications of the braking system in combination with the electric drive.”
Among other things, we retrofitted the truck with high-quality measuring systems for data logging, two braking systems (EBS5, GSBC), various driver assistance systems (ABS, ATC, ESP) and a fifth wheel coupling for additional trailer operation.
György Surek – Design and Test Engineer at eVMC-Software
During the eVMC test weeks, which took place regularly every two to three weeks in the third quarter of 2023, road tests were performed to further optimize and develop the product. The eCUBATOR team used predefined eVMC test series to check and fine-tune the basic functions for energy recuperation.
The entire eVMC product development was an iterative process based on the SCRUM methodology. A strengths and weaknesses profile for key features, including energy recuperation and braking distance, was used to identify potential improvements and set up follow-up tests. For design engineer Surek, the results were positive: “We managed to increase driving performance with eVMC. The energy balance appears to have improved. Now we have to wait for comparative measurements to obtain a quantitative result.”
Interdisciplinary and international teams have been working together at Knorr-Bremse since the end of the 1990s. I find the eCUBATOR team spirit inspiring. When we are conducting test series and exchanging our expertise in person, there’s an extremely high pace and efficiency to the process. Everyone is willing to go the extra mile to find the right solutions together.
Martin Mederer (left) – Product Line Owner “Brake Control” for eCUBATOR
The positive results from the summer test series at the ZalaZONE test track were fully confirmed in winter testing in Arjeplog (northern Sweden). During the driving tests in Arjeplog , the eVMC functions were thoroughly tested under extreme conditions. Particular emphasis was placed on optimizing energy recuperation, but the transitions of the service brake function with recuperation were also examined with regard to ABS/ESP. Overall, the functionality can now be described as having reached stable B-sample status.
The eVMC functions are currently being handed over to the Center of Competence (CoC) Brake Control for series application. Following successful implementation in the GSBC, the software package will be available to customers. The specialists at the CoC Brake Control will apply the systems to various vehicle types – because the product must work reliably and efficiently in various truck models with different tonnages and electric motor outputs. In addition, the software has to represent multidimensional drive concepts for trucks: those with a combustion engine, with an electric motor at the wheel end or with one electric motor per axle (outside Europe).
For “Eddy”, the journey continues. In the future, other eCUBATOR products and systems will be installed and tested in electric trucks, such as an oil-free compressor for use in electrically powered commercial vehicles. “Eddy” is therefore playing a key role in the ongoing development of Knorr-Bremse’s e-mobility product portfolio. Martin Mederer is looking forward to the challenges ahead: “It’s an extraordinarily exciting period of development that we are involved in with our eCUBATOR colleagues in Munich and Budapest – and on the road with ‘Eddy’.”
Knorr-Bremse has been relying on Martin Mederer’s expertise for 35 years. Initially, the brake control engineer was involved in developing driver assistance systems such as ASR, ABS and EBS. Martin Mederer later worked at Bendix in the United States and specialized in trailer brake control. He has now been working in the eCUBATOR development unit for three years, and his motivation is simple: “To discover, do and develop new things – and to move with the technology.” The words of a true engineer!
György Surek is the design and test engineer responsible for eVMC in the eCUBATOR unit in Budapest. He has extensive knowledge of mechanical engineering and gained his first professional experience in electrification in the passenger car industry. For over a year now, György Surek has been working tirelessly on the further development of electric trucks in the eCUBATOR team at Knorr-Bremse. As a thoroughbred engineer, Surek’s tasks here include working on the design and electrics of “Eddy” in preparation for the test series.