Japanese car manufacturers had a monopoly on hybrid vehicles for almost a decade. Initially sneered at and viewed as an eternal loss-making business, these cars are also boosting the company’s sales figures – Toyota and subsidiary Lexus have so far sold over a million units. And not only that: since the discussion surrounding rising energy prices, scarce oil reserves and the threat of climate change started, the hybrid drive is being seen by politicians and society as a pioneering automobile concept for the future.
European manufacturers have taken up the challenge, and we will soon know what their choice of solution looks like – all of the major groups are working intensively on hybrid models that will be launched in the next few years. So, something’s brewing in the automobile industry and IAV is right at the center of all: as part of research and advance engineering projects – such as in 1998 in the uni1 partner project – the company has been developing hybrid drives for years. IAV is now putting this expertise into mass-production development. And the know-how that has amassed is also very much in need – being regarded among carmakers as the “royal league of system integration”. All disciplines must be included in optimization which also means: the developers must communicate even more closely – for instance, the programmer of the engine control system must keep in contact with his colleague from the brake development department. For Wilfried Nietschke, head of the Powertrain Mechatronics (SI Engines) business area, this is why the hybrid is also “the jump-start for new technologies and an opportunity for lateral thinkers”.
There is indeed a lot to think about in hybrid development, particularly on the energy management side: voltages of up to 400 volts and currents as high as 50 amps occur in these vehicles. This is why the developers have to think even more carefully about the vehicle electrical system – and, in designing the system and components, attach particular importance to safety. In “energy harvesting” it is a matter of optimizing the efficiency of every component in the vehicle as far as possible, thereby reducing CO2 emissions. These endeavors ultimately benefit conventional vehicles too, e.g. through better electric generators or demand-controlled auxiliaries. As such, hybrid development is also helping to make motor-vehicle traffic more ecologically friendly all told.
The boundaries are fluid anyway, because the innovative drive concept can be implemented in numerous versions – in the form of the modest micro-hybrid through to the mild-hybrid and on to the full hybrid. In addition, the developers can decide whether the electric motor is to serve the primary purpose of saving energy or rather to act as a boost for greater driving dynamics. The new degrees of freedom make selection all the more difficult. This is why simulations are becoming increasingly important in development work because they provide the basis, early on in the process and without all too much cost, for estimating the vehicle’s later characteristic properties and deciding between different options. In addition to computation, IAV uses a further simulation tool: in the “InDrive Simulator”, developers and test drivers can try out the future car even before building the first prototype.
German manufacturers stand a good chance of catching Toyota up. The answer lies in using their very own strengths, such as with the diesel hybrids that combine an extremely economical combustion engine with an electric motor and thus unite the best of both worlds in one vehicle. This, however, comes at additional cost and is therefore only of interest for higher-class vehicles. Generally speaking, experts are expecting hybrid vehicles – at least the full hybrids – to remain a niche product in the medium term on account of cost despite their indisputable advantages. But a little bit of hybrid, say in the form of a start-stop system, will soon be encountered in every car.
And the subject is getting things moving in the industry on one other score: the hybrid revolution is attracting new suppliers that have so far gathered hardly any experience with the specific requirements in automobile engineering. From the aspect of system integration, it is therefore particularly important for experienced companies, such as IAV, to help the newcomers develop their products – e.g. the additional electronics or rechargeable batteries – in such a way that they are suitable for use in mass production. Because the extreme levels of stress on materials and the exacting demands placed on safety make it impossible to simply carry over solutions already existing in industry. “That would not work which is why we must develop everything to suit the type of vehicle concerned “, says Wolfgang Reimann, Vice President of Vehicle Electronics at IAV.