故障树分析的二元决策图方法

为了克服故障树方法分析复杂系统存在的不足,引入二元决策图理论,把故障树转化成二元决策图;然后自上而下遍历二元决策图,得到最小割集和顶事件发生的概率.二元决策图转化过程中,基本事件的排序直接影响二元决策图的结构大小.在不改变故障树逻辑关系的前提下,先对故障树进行简化,除去一些冗余的部分;然后从故障树结构重要度的角度,对简化后故障树的基本事件进行排序.实例证明所采用的基本事件排序方法是有效的,能够简化故障树定性和定量分析过程.

Fault tree analysis based on Binary Decision Diagrams

In order to overcome the deficiency of fault tree analysis （FTA）, the Binary Decision Diagram （BDD） method was introduced to convert a fault tree to a BDD and obtain the minimal cut sets and the exact top event probability by traversing the resulting BDD from up to bottom. An ordering of the fault tree basic events had a crucial effect on the size of the resulting BDD. The basic events ordering method proposed in this paper first implemented a simplification technique for the fault tree to remove redundant terms without changing the underlying logic, and then the basic event of the simplified fault tree could be ordered from a structure importance point of view. An example illustrated that the basic events ordering method presented in this paper was efficient, and the resulting BDD could simplify both qualitative and quantitative analysis of the fault tree.