Reliability evaluation of the power supply of an electrical power net for safety-relevant applications

In this paper, we introduce a methodology for the dependability analysis of new automotive safety-relevant systems. With the introduction of safety-relevant electronic systems in cars, it is necessary to carry out a thorough dependability analysis of those systems to fully understand and quantify the failure mechanisms in order to improve the design. Several system level FMEAs are used to identify the different failure modes of the system and, a Markov model is constructed to quantify their probability of occurrence. A new power net architecture with application to new safety-relevant automotive systems, such as Steer-by-Wire or Brake-by-Wire, is used as a case study. For these safetyrelevant loads, loss of electric power supply means loss of control of the vehicle. It is, therefore, necessary and critical to develop a highly dependable power net to ensure power to these loads under all circumstances. q 2005 Elsevier Ltd. All rights reserved.