飞机系统安全性指标的Petri Net分配方法

为解决动态故障树抽象而不利于交流的问题,利用Petri Net直观、易用且适用范围广的优点,提出基于Petri Net的飞机系统安全性指标分配方法。通过整理安全性指标及其相关的可靠性指标,选取失效率作为安全性指标,对比动态故障树及Petri Net建模方法,选取后者建立静态逻辑变迁和动态逻辑变迁的Petri Net指标分配模型。在此基础上,提出考虑严酷等级的系统安全性指标分配方法,经过算例分析,构建Petri Net层次系统故障模型进行指标分配。结果表明,分配值均在相应安全性指标内,该方法能够克服动态故障树法不直观、等分配法分配过于粗糙等缺陷,为飞机安全性设计与评估提供参考。

Petri Net distribution method for aircraft system safety index

To solve the abstractness and communication difficulties of dynamic fault tree, this paper proposed a distribution method based on Petri Net for system safety index by utilizing the advantages of Petri Net including intuition, easy and wide application, it selected failure rate as a safety index through arranging the safety index and related reliability index, By comparing the modeling methods between dynamic fault tree and Petri Net, it chose the latter to establish index distribution models for static and dynamic logic changes. On the basis of this, it introduced hash classification, for the refinement of system safety index distribution to a certain extent. And through example analysis, a Petri Net hierarchical model for system faults was constructed to distribute index. Distribution results demonstrated that all distributed values were within corresponding safety indexes, and this method could overcome the defects of non-intuition in dynamic fault tree method and of excessive roughness in equal distribution method, providing references for the design and evaluation of aircraft safety.