基于贝叶斯网络的城市轨道交通CBTC系统SIL研究

城市轨道交通CBTC系统是一个安全苛求系统,为了更好地分析CBTC系统的安全性,首先通过对整个系统自顶向下分析,对各子系统和单元模块的功能进行划分,建立CBTC系统的贝叶斯网络,然后再自下向上由子系统级别到整个CBTC系统级别逐步计算出CBTC系统的平均故障率,最后从系统失效的角度验证系统的安全完整性等级(Safety Integrity Level,SIL)。结果表明,在系统硬件设备的故障率不变的情况下,可以通过调整子系统的冗余结构,增加整个CBTC系统的容错能力来提高其随机故障的完整性,使得系统符合安全标准要求。

Research on SIL of CBTC System of Urban Rail Transit Based on Bayesian Network

CBTC system of urban rail transit is a demanding security system. In order to better analyze the security of CBTC system,the functions of subsystems and unit modules are divided and Bayesian network of CBTC system is established through top-down analysis of the entire system. The failure rate of CBTC system is then calculated bottom-to-top from subsystems to the entire CBTC system. Finally,SIL of the system is validated in perspective of system failure. The results show that fault-tolerant capability of entire CBTC system can be increased by adjusting redundant structure of subsystems to improve completeness of random failure and meet the safety standard requirements under the condition that system the fault rate of hardware equipment remains unchanged