Reliability analysis of brake-by-wire systems on fault tree

Abstract

Brake-by-wire (BBW) system is the key system to ensure the safety and stability control of intelligent vehicle chassis. How to evaluate the BBW systems to meet the safety design requirements is one of the important links of system design. This article takes the BBW system as an example to illustrate the basic process of the safety assessment of intelligent vehicle. The fault tree analysis (FTA) method is used to quantitatively evaluate the failure status of the complete loss of the main brake function, and the fault tree analysis process is detailed. The results show that FTA plays an important role in guiding the design of system architecture. With the help of the importance index, we can quickly find out the weaknesses in the system architecture, when the probability of the failure state of the automobile brake-by-wire system cannot meet the ASIL requirements. Furthermore, effective countermeasures can be taken to optimize the design of the system architecture. Finally, the failure probability corresponding to the failure state of the car's brake-by-wire system is reduced to 7x10-14