基于模糊故障树的列控风险发生频率研究

Research on Risk Occurrence Frequency of Train Control System Based on Fuzzy Fault Tree

引入模糊数,采用基于模糊故障树的计算方法对列控风险发生频率等级进行计算。该方法首先采用故障树对需要进行发生频率等级评估的列控风险进行描述,对于有统计数据信息的基本事件的发生频率采用精确值表示,对于没有统计数据信息的基本事件的发生频率采用模糊数表示;之后采用模糊算子对顶事件的发生频率进行计算,得到顶事件的模糊数;然后采用重心法对顶事件的模糊数进行去模糊化,得到顶事件的发生频率精确值;最后依据风险发生频率等级表确定风险的发生频率等级。以道岔中风险为例进行计算,计算结果验证了基于模糊故障树计算方法的有效性。

The fuzzy number is introduced and the fuzzy fault tree is used to calculate the risk occurrence frequency of the train control system. First,the events required for frequency grade assessment are described by the fault tree,the frequencies of basic events with statistical data are represented by exact values,while the frequencies of basic events without statistical data are represented by fuzzy numbers.Then the fuzzy operator is used to calculate the frequency of the top event and the fuzzy number of the frequency of top event is obtained. The fuzzy number of the top event is defuzzified with centroid method to get the exact frequency of the top event. Finally,the risk frequency level is determined by the level table of the risk frequency. The risk of the switch is cited as an example for calculation and the results show that the fuzzy fault tree method is effective.