Impact of Automated Driving on Design and Energy Consumption of Electrified Drives

This paper discusses the dependency between powertrain design and automated driving. The research questions are to what extent automated driving influences the powertrain design and how energy and fuel consumption is affected in comparison to customer driving. For this investigation a concept study is carried out for a D-segment vehicle and multiple powertrain topologies, ranging from non-electrified to plug-in hybrids and battery electric vehicles. In order to answer the research questions, the used development process and the methods for optimizing the drive system are presented accordingly, taking into account all vehicle requirements, the drive system and the components and their interactions with each other. This work focuses on two automated driving functions developed at the Institute of Automotive Engineering of the Technische Universität Braunschweig. The functions are an “automated valet parking” and a “highway pilot”. The hardware architecture required for automated driving functions lead to an increase in vehicle mass and auxiliary power consumption. Furthermore, the automated driving functions result in changed driving profiles. Driving cycles were generated on the basis of measurement data from the automated functions and compared with the customer's driving operation. The results show, that an energy reserve for an automated valet parking function leads to a reduction in the all-electric range up to 12 km for battery electric vehicles and 7 km for plug-in-hybrids and thus also to up to 2 g/km higher combined emissions. It has also been shown that the impact of the highway pilot to energy and fuel consumption in customer operation is significantly influenced by the customer's driving style and the additional consumption for the automated driving function, with battery electric vehicles having the highest savings potential.