“The combustion engine has been and will continue to be subject to intensive and successful research and development!”

An interview with the experts at the Steinbeis Transfer Center Automotive Engineering Esslingen

Professor Walliser, it has now been 20 years since you set up the Steinbeis Transfer Center (STC) for Automotive Engineering in Esslingen. The automotive industry moves forward at breakneck speed, so two decades are tantamount to an eon. What were your areas of focus in those days and how have they changed over time?

The founding of our Steinbeis Transfer Center was strongly motivated by recommendations from the automotive industry. It was a time of crisis and the industry wasn’t really recruiting even though the contracts and money were there. Graduates had little hope of finding a job so we took them on at Steinbeis. This was a great help for industry and graduates. When we set up our STC we were consciously not setting up a “company” with workers; it was just about making the know-how of co-workers and the modern university infrastructure available to trade and industry. We now have 17 experts with backgrounds in all fields of vehicle development. The emphasis at the moment lies in drive systems, services and international courses for students and engineers from China, India, Mexico, etc.

Twenty years ago there wasn’t much on offer in the way of IT or electronics training for engineers specialized in mechanical engineering and vehicle technology, and it was difficult to get across how important control technology was for vehicles that didn’t have electronics. Now these subjects are core components of the training. It was hardly possible to imagine how quickly navigation or semi-automated driving would make it into serial production. The international Promotheus project was a tremendous help at the beginning and our STC had small overlaps with it. Today, fully automated, accident-free driving is at the top of the list when it comes to vehicle developments, on a par with electric, hybrid and fuel cell-based drive systems, although nobody’s really able to say how much of this will really make it into mass production. When it comes to electric cars, the main problems still lie with the battery; with fuel cell vehicles, there’s also the price issue. But of course we shouldn’t overlook the fact that the combustion engine has been and will continue to be subject to intensive and successful R&D!

Professor Rottenkolber, Professor Walliser, your Steinbeis Enterprise also looks at the field of vehicle mechatronics. This is a topic that’s opening the door to lots of new opportunities, but more than anything, it’s posing new challenges in terms of globalization. What do you see as the problem areas in the industry at the moment?

One megatrend of the future, which could be made possible by mechatronic systems, is autonomous driving. It looks like it will be possible within the next decade for intelligent electronics to take on the role of the driver. Modern radar and camera-based driver assistance systems, which are already available in serial production vehicles, have already helped make the first step toward this vision of the future. So it’s just a matter of time before the systems are developed far enough to watch traffic around the car and steer, brake and accelerate the vehicle by working together with a powerful computer. Despite the imaginative ideas of the engineers and the sheer scope of technical feasibility, the emphasis in development should still always lie in the needs of the driver, in all kinds of regions throughout the world. All these new assistance, comfort and safety systems will require more energy from vehicles and it’s not yet understood what demands this will place on the car electronics. The current 12V wiring systems are reaching their limits because they can’t cope with more than 3 kilowatts (kW). Top-of-therange vehicles now need a lot more at maximum performance. There’s been lots of discussion about e-chargers for vehicles with combustion engines but they’ll need even more energy. One solution could be a new car electronic system running on 48 volts; that would provide up to 12kW of power. Hybrid cars already have high-voltage circuits of up to 400 volts, but the extra cost is significant compared to a 48-volt system. But these are just two examples of the types of vehicle technology trends that are made possible by mechatronic systems. Almost every area of the vehicle market is now dominated by mechatronics, whether it’s the drivetrain using more electricity, the active chassis or automatically operated parts in the car body.

Professor Rottenkolber, automotive engineering now faces highly complex demands: everything has to be profitable, environmentally friendly, safe and easy to use. All of these factors are strongly influenced by the drivetrain. What do you think is the best way to make power trains clean, inexpensive and cost-efficient?

The innovation drivers in automotive engineering, especially in the drivetrain, are efficiency improvements and environmental friendliness. By 2021 the CO2 limit for fleet consumption will be 95 g/km. The limit for toxic contaminants will also become stricter throughout the world, even by making changes in driving cycles. But at the same time, travel is supposed to be affordable. When the demands get this complex there’s usually not a simple technical solution. Drive developments will still be dominated by combustion engine optimizations for years to come. It’s a highly complex unit within the overall system of the drivetrain, so, as it is today, there will still be potential to make more efficiency improvements and preserve resources at a moderate cost in the future. This applies just as much to classic combustion engines and the drive system itself as it does to a combination with an electric motor (as is the configuration in different versions of hybrid systems). Concepts for downsizing – i.e., small engines with exhaust gas turbocharging – are a huge challenge in terms of construction and materials design. Another focus lies in technologies for reducing friction. Looking at other areas in which our center has been conducting research for years, there’s also more potential for lowering consumption and emissions by further optimizing existing combustion methods and developing the combustion concepts of the future. But new fuels will also play a major role in developments in the future. In the next few years, one of the most important trends in the automotive industry on the road to sustainable motor transportation will be ongoing developments in electric vehicles and their introduction to serial production. The main driver of this is the goal of reducing emissions in many areas of the world, especially in mega-cities. People have been developing fuel cells for decades to extend the range of electric vehicles and they’re on the verge of serial production. But an eye has to be kept on the effort and cost of producing these new types of drive technology, as well as the costs of alternative energy formats.

Professor Wolfmaier, materials and the production methods used for vehicle chasses continue to move forward and this is placing new demands on developers and producers. Where do you see the greatest need for action?

For decades, the onus has been on carbody engineers to keep up with the constantly more demanding requirements of legislators in terms of emission controls and vehicle crash safety, mainly in relation to lightweight design. This has been exacerbated by the fact that customers have gotten used to high expectations in terms of comfort. The target values for average carbon emissions, which legislators are expected to set for vehicle fleets in the coming decades, will no longer be possible to achieve by just making conventional developments in materials and production processes. This is why the focus lies in developing new power trains. Evehicles have an important role to play in this respect, but with them comes a monumental growth in the weight of the overall vehicle. Chassis carbody engineers have to compensate for the additional weight by coming up with new lightweight design concepts.

Discussion also currently revolves around the protection of passengers during accidents and crash setups that provide backseat passengers with better protection. Legislators have also been turning the spotlight more on pedestrians involved in accidents with vehicles in recent years and this has a bearing on measures in the front section of vehicles. So lightweight design will remain a focal topic for chassis developers. Fiber-reinforced materials could play an important role in this area, as well as more established lightweight materials like high-strength and ultra high-strength steel, aluminum and magnesium. But at the moment it’s not worth using carbon fiber composites in mass production, neither for commercial nor for ecological reasons. It’s still early days for fiber composites and research into structural durability and crash properties. So we need interdisciplinary teams from the engineering sciences to keep developments moving forward and to ensure we find new materials, new production methods and new assembly techniques. The world of automotive development has to meet the environmental demands made by lawmakers. Only with extreme efforts in R&D will it be possible to make motor transportation safe, environmentally friendly and comfortable.

Professor Dipl.-Ing., Prof. h.c. (YZU) Gerhard Walliser und Professor Dr.-Ing. Gregor Rottenkolber are directors of the Esslingen- based Steinbeis Transfer Center for Automotive Engineering. They have been working intensively in the area of vehicle power trains and vehicle mechatronics. Professor Dipl.-Ing. Christof Wolfmaier is deacon of the automotive engineering department at Esslingen University of Applied Sciences and is a project manager at the center.

Professor Dipl.-Ing., Prof. h.c. (YZU) Gerhard Walliser
Professor Dr.-Ing. Gregor Rottenkolber
Professor Dipl.-Ing. Christof Wolfmaier

Steinbeis Transfer Center Automotive Engineering Esslingen (Waiblingen)

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