To meet the safety requirements for emergency braking of Metro EMU,the tolerable functional failure rate of the emergency braking circuit is determined in accordance with the risk acceptance criteria specified in EN 50126-1:2017 Railway applications-The specification and demonstration of reliability,availability,maintainability and safety(RAMS)-Part 1:Generic RAMS process.Based on the existing emergency braking circuit scheme,a fault tree is con-structed and the functional failure rate of the emergency braking circuit is calculated.The reasons that the existing scheme does not meet safety goals are analyzed.From multiple aspects such as emergency braking triggering conditions and product failure detection methods,the existing emergency braking circuit scheme is optimized.According to calcu-lations,the safety of the optimized emergency braking circuit has been effectively improved,safety requirements are met.
Metro EMUEmergency Brakeing CircuitSafetyFault Tree
NETL
NSTL
万方数据
