Abstract: To effectively evaluate the reliability of k-out-of-n systems with K-mixed redundancy strategy,particularly when unit failures follow arbitrary distributions and the minimum number of operating units k>1,a reliability modeling method based on dynamic fault trees was proposed.Spare gates were employed to describe the dynamic behavior caused by unit failures and spare replacements,and conditional events were defined to transform the dynamic gates into static gates.Further,Conditional Binary Decision Diagrams (CBDD) were used to qualitatively analyze the model to identify all minimal cut sets that may lead to system failure.For minimal cut sets containing different types of time-dependent failure events,corresponding probability calculation methods were proposed to determine system reliability.The method was validated through reliability analysis of an aerospace actuator under different unit distributions and system configurations,demonstrating its high computational accuracy and efficiency.

Key words: K-mixed redundancy strategy, k-out-of-n systems, dynamic fault trees, conditional binary decision diagrams, temporal failure events

摘要： 为对采用K-混合冗余策略的n中取k系统可靠性进行有效评估,特别是在单元失效服从任意分布且最少运行单元数量k>1的情况下,提出一种基于动态故障树的可靠性建模方法。利用备件门描述单元失效和备件替换所产生的动态行为,并定义条件事件对动态门进行静态化处理;进一步使用条件二元决策图(CBDD)对模型定性分析,得到所有可能导致系统失效的最小割集;针对包含不同类型时序失效事件的最小割集,提出相应的概率计算方法,以此求得系统的可靠度。最后以某航天器的执行机构为例,针对不同的单元分布和系统构型进行可靠性分析,结果表明该方法具有良好的计算精度和更高的计算效率。

关键词: K-混合冗余策略, n中取k系统, 动态故障树, 条件二元决策图, 时序失效事件