Test halls for electric cars
Electric cars are already an attractive alternative for many people. This revolutionary drive technology raises new questions both for researchers as well as commuters.
When will we see the electric car overtake the internal combustion engine?
For Thomas Reimer, Head of Vehicle Mechatronics and Mobility at the Research Institute of Automotive Engineering and Vehicle Engines in Stuttgart (FKFS), it is a question he hears often. His response:
“Why do we need to drive out the combustion engine? Petrol and diesel engines have coexisted for decades, and we haven’t been asking which will replace the other all that time.”
Riemer and 240 of his FKFS colleagues tackle many questions concerning changes in the automotive sector. Key areas include, for example, the functional safety of a vehicle’s electrical components.
Software is replacing mechanics
Riemer and his team are currently dealing with many different questions:
- What happens in the electric drive train if individual electric components malfunction?
- How can unwanted acceleration be prevented in multi-motor concepts, in which each wheel has its own electric motor?
- How can I regain control over assistance systems in order to avoid an accident?
These questions give an inkling to the array of new topics around electric vehicle motorization that were not asked for conventional drive technologies.
Research results flow directly into the development of new vehicles, as the FKFS institute, initially started as a foundation , acts as a nexus between the university and businesses. The institute addresses inquiries from the business world, providing firms with results from university research.
Working with DEKRA
FKFS has also worked together with DEKRA for many years. Collaborative projects included expanding the scope of general inspections using vehicle diagnostics interfaces, as well as accident reconstructions using diagnostic information.
For now, however, the task is to subject one of FKFS’s test vehicles to a general inspection. Riemer will drive the test vehicle — a Mercedes B Class equipped with various analysis technologies, cameras ,and measurement sensors — into the test hall at DEKRA’s headquarters in Stuttgart.
For DEKRA Test Engineer Peter Chromik, the inspection process of an electric vehicle is similar to that of a vehicle with a combustion engine. After checking the headlights and other lighting elements, it is on to the brake testing rig and the hydraulic lift.
“Now the emissions test,” Riemer shouts, as Chromik slowly raises the lift. The visual inspection of the brakes does not identify any issues. The car has no exhaust muffler or dripping pipes. “No leaks,” chuckles Chromik in reference to the absent parts, such as the oil reservoir and fuel tank, before adding:
“There are fewer and fewer mechanics and more and more software involved.”
Stickers and insulation
The general inspection of electric vehicles also employs a vehicle diagnostics adapter to identify faults, for example in the electronic assistance systems. Similarities end beneath the hood; it is hard to draw any parallels between electric and conventional vehicles here.
Stickers warn for high voltages, and all cables have been extensively insulated. Again, the DEKRA engineer carries out a visual inspection, checking whether any cables have loosened, or if any insulation has been damaged. No problems are found with the battery. Riemer:
The battery presents no more or less a hazard than liquids or gaseous fuels
Private infrastructure?
One challenge to the wider acceptance of electric drives is their practicality, Riemer adds. It isn’t the number of publicly accessible charging stations and superchargers along major routes that present an issue, but it is the infrastructure on a private level.
“Electric cars are likely to be overlooked by city-dwellers — who would want to drive an extra two blocks hoping that the charging station is working and available, then returning hours later to collect their vehicle?”
Buildings containing multiple dwellings also face infrastructure issues: “If 30 vehicles need to be charged simultaneously, the mains connection to the building is likely to be overloaded”, Riemer says.
“In Germany, for example, there is limited demand for EVs,” says Riemer. This could be attributed to the general perception that EV ranges are still limited. “Many people somehow believe that they are long distance drivers, even if they mostly drive short distances.” Such people would gain the most from driving electric.
Diversifying performance
One approach to increase consumer acceptance is by diversifying electric vehicle performance classes. Conventional cars offer customers a choice of various engine performance classes. Electric vehicles often grant them only a single choice.
Introducing models with a range of battery sizes could allow manufacturers to offer various performance levels and vehicle ranges. The general inspection will also change as vehicles evolve.
“Vehicle technology is developing rapidly, and the general vehicle inspection needs to adapt to current vehicle developments. It increasingly resembles a mechatronic assessment,” Test Engineer Peter Chromik explains, as he carefully affixes an inspection sticker to the FKFS’ Mercedes B Class.
The electric vehicle then leaves the DEKRA test hall with a faint hum, ready to collect even more valuable driving data.
