Abstract
Keywords: brake-by-wire, reliability, (MX) FMEA
Active safety systems (EBS, ESP) address known safety problems but also introduce new classes of potentially hazardous failure modes. In a traditional design, in which the driver´s input defines the energy level, for example, a commission failure such as the inadvertent application of brakes on a single wheel of the car is impossible. This condition becomes possible, however, in a design that enables independent by-wire control of wheel brakes. Active safety functions that control such brakes are of course carefully designed to fail-silent in case of detected malfunctions. But although the likelihood of commission failures can be reduced via good design, the potential still remains. The severity and probability of occurrence of these and other failure modes likely to arise from the introduction of new technologies in vehicles, therefore, need to be carefully considered to ensure safe deployment of such technologies.
Understandably, such radical design changes raise serious safety concerns and demand the thorough safety evaluation of any new design concepts. Potential failure modes must be identified and the effects of these failure modes in the provision of sensitive active safety functions must be established. (Papadopoulos, 2004)
This paper demonstrates a qualitative reliability analysis using (Matrix) FMEA applying to a partly redundant semi-trailer electronic brake system paying attention to the steps of a correct procedure of handling redundant systems with classical reliability approach starting from the system definition through function deployment finishing with evaluation.