Search Results

The new generation of drive-by-wire systems currently under development has demanding requirements on the electronic architecture. Functions such as brake-by-wire or steer-by-wire require continued operation even in the presence of component failures. The electronic architecture must therefore provide fault-tolerance and real-time response. This in turn requires the operating system and the communication layer to be predictable, dependable and composable. It is well known that this properties are best supported by a time-triggered approach. A consortium consisting of German and French car manufacturers and suppliers, which aims at becoming a working group within the OSEK/VDX initiative, the OSEKtime consortium, is currently defining a specification for a time-triggered operating system and a fault-tolerant communication layer.1 The operating system and the communication layer are based on applicable interfaces of the OSEK/VDX standard.

In autumn 1991 BMW presented to the public its first, specially designed electric vehicle, the E1 concept study. With this car all the future requirements of electric vehicle components were fulfilled. Notable is the brake system layout and the resulting possibility of recuperation. This report shows the theoretical potential of recuperation for different driving profiles and for the most important drivetrain concepts. According to the chosen control concept a variable utilization of this potential is being achieved. The important criteria to be considered - for example legal requirements, light weight design, the relation of cost and use - will be demonstrated by the braking layout of the BMW E1 concept car. Moreover still existing problems will be shown.