No abstract

The relevance of safety applications within the automotive industry is increasing continuously, for example due to vehicle automation and decreasing performance of mechanical backups. To cope with these trends, the power supply of safety-related electrical and/or electronic systems needs to be ensured. This leads to increasing functional safety requirements. Compliance with ISO 26262 will be more in focus in the future. Currently, the compliance with ISO 26262 may be used to argue the state of the art focusing on product liabilityhowever, it will become mandatory for homologation in the future. Thereby, the power supply system is a crucial point since faults of the power supply system are currently the major contributor for vehicle breakdowns with increasing tendency. So far, there is no standard approach within the automotive industry how to ensure functional safety for power supply systems. To fill this gap, this technical elaboration evaluates functional safety with focus on power supply system development. Hence, guidelines on how to apply the ISO 26262 are provided based on discussions within the automotive industry and research institutes. The focus is on the concept phase, i.e. item definition, hazard analysis and risk assessment, and the functional safety concept. The functional safety concept is based on a structured hierarchical breakdown to systematically derive safety requirements from the item level down to the power supply system level. The essential requirementbeside the safe power feed and safe power distributionis to assure the freedom from interference between the safety and non-safety relevant components.

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No abstract

To find an answer to the question 'how to design low-noise manual automotive transmissions', it is essential to look at numerous external and internal measures which have already been developed to reduce rattle and clatter proneness. Only very few have been used in mass production. The use of these measures depends not only on the degree of noise reduction achieved but also on the production engineering and economic parameters. The wear characteristics and the level of power loss and the intrinsic noise involved must also be taken into account. Each transmission system and each driveline system must be individually adapted from the large number of various possible solutions. This study focuses on of existing and new measures in the literature and some experimental results which were investigated at the University of Stuttgart Institute of Machine Components. The aim was to create an engineering design catalogue for low-rattle and -clatter manual automotive transmissions using the systematic measurements and the knowledge derived from experience.