Abstract
Keywords - automatic transmission, hybrid, reuse, modulare software architecture, development time
As a result of continuously rising requirements relating to the reduction of fuel consumption and emissions, another optimization of the ZF 6-speed transmission system does not pave the way to success. Therefore, ZF has decided in favour of the development of an automatic 8-speed transmission which, in comparison to an optimized 6-speed transmission, will generate fuel consumption advantages. In the course of the 8-speed basic transmission development, a modular system has been established which entails future hybridization without major mechanical modifications.
One of the objectives of electronics development resides in the fact that the modular system of mechanics is reproduced. Thus, a modular software architecture was drawn up, which can be used with both units, the basic transmission as well as the hybrid transmission.
In software architecture, the hybrid drive constitutes a further development of the basic transmission, namely by the operational hybrid functions component. Consequently, efforts for implementation and testing can be reduced severely when compared to completely new hybrid transmission architecture. By means of clearly defined interfaces, different development processes can be used for the components, i.e. programming in C++ and modelbased development with CASE tools. In the course of the changeover process from 6-speed transmissions to 8-speed transmissions, a similar approach could be used for software architecture i.e. the time from start of programming up to the initial software release with the first prototype was reduced to 6 months.
In the case of a completely new implementation, delivery in such a short period would not have been possible. As a result, modular architecture does not only reduce development efforts but also actively contributes to shorter development times in product development. By means of the "ReUse" strategy, well-proven high quality components are being used which help to significantly reduce failure rates.