系统安全性分析方法是目前广泛采用的飞机安全性设计方法。由于在分析中缺乏对系统整体动态特性的检查,在设计中可能存在可靠性指标分配的不合理。通过面向安全性的风险评估,能够实现系统动态特性的综合验证。提出了一种基于割集和重要度的故障树可靠性指标分配方法,以某型飞机横向电传操纵系统安全性设计为例对顶事件不可靠度指标进行分配,然后结合基于极值理论的飞行风险评估实现了部分底事件可靠性指标的修正。
The system safety analysis is widely used in the safety design of an aircraft. For lack of checks for dynamic characteristics of the whole system, the distribution of some reliability indexes may not be reasonable. A comprehensive verification of system dynamic characteristics can be realized through the safety-oriented risk assessment. This paper proposes a new method of distributing the reliability index for Fault Tree Analysis (FTA), based on the cut sets and the importance measure. With the safety design of the Fly-By-Wire (FBW) system for an aircraft's rolling channel as an example, the fallibility index of the top event is distributed. Then the distributed reliability indexes are modified, combined with the flight risk assessed by the Extreme Value Theory (EVT), which plays an important role in the system safety analysis.