采用故障树分析诊断系统故障的改进方法

An improved method for system fault diagnosis using fault tree analysis

为了优化系统诊断过程,提出一种采用故障树分析诊断系统故障的改进方法.通过故障树分析,求出所有最小割集、最小割集发生概率、组成单元的诊断重要度.诊断重要度大的最小割集优先诊断,最小割集中诊断重要度大的组成单元优先诊断.当最小割集中诊断重要度最大的组成单元故障时,包含该组成单元的最小割集应该优先诊断.根据组成单元的诊断顺序,生成系统的诊断决策树.这种方法弥补了仅以组成单元的诊断重要度确定最小割集诊断顺序的不足,使得发生概率大的最小割集可以优先诊断,优化了诊断过程.通过实例验证了该故障诊断方法的有效性.

This paper proposes an improved method to diagnose system faults using fault tree analysis to optimize system diagnosis.All minimal cut sets,their occurrence probabilities and the diagnosis importance of components were determined via fault tree analysis used for system reliability.The order by which the minimal cut sets were checked depended on the diagnosis importance.Components with larger diagnosis importance within a cut set were checked first.Meanwhile,the minimal cut sets containing the component with the largest diagnosis importance were also diagnosed first when the component was fault.According to the diagnostic sequence of system components,a diagnostic decision tree was generated.This method offsets the insufficiency caused by the diagnostic sequence which is merely determined by the diagnosis importance of components.Therefore,the minimal cut set which has larger occurrence probability can be checked first,and the system diagnosis is optimized.An example is given to demonstrate the efficiency of this method.