针对扩展动态故障树的约束分析方法

Constraint analysis for extended dynamic fault tree

提出延时门机制对动态故障树进行扩展,用于对子系统失效延时传播到上层系统进行建模,并通过扩展动态贝叶斯网络对包含延时门的动态故障树进行求解。还提出并实现了一种基于可满足性模理论的扩展动态故障树求解算法,支持由非确定性的基本事件概率范围约束求解系统的最优化失效率。通过对实际系统的分析、求解及与现有工具的对比,说明分析方法的有效性,并通过对实际系统的分析给出了基本事件概率约束和延时门参数对系统整体失效率的影响。

As a new extension of dynamic fault trees,time delay gate was proposed.This new mechanism can be used to model the time delay on the fault propagation from the lower level subsystems to the higher level system.The dynamic Bayesian networks was extend to solve the dynamic fault trees containing time delay gates.An algorithm based on SMT to support the optimized failure distribution under the nondeterministic range constraint of basic events was also proposed.The effectiveness is shown by comparison with existing tools on analyzing and solving real systems,and the effects of range constraints and gate parameter on the failure distribution of systems is illustrated.