凸模型T-S故障树及重要度分析方法

Convex Model T-S Fault Tree and Importance Analysis Methods

针对故障数据缺乏、故障机理复杂多样等原因导致T-S故障树底事件的失效可能性具有不确定性的问题,以及概率和模糊T-S故障树以及布尔逻辑门故障树适用性的不足,提出凸模型T-S故障树及重要度分析方法:将区间模型引入到T-S故障树分析方法中,利用区间模型描述底事件的失效可能性,提出区间T-S故障树分析方法,解决底事件的失效可能性不易精确获取的问题;在此基础上,引入超椭球模型来界定不确定性参量的取值范围,进而提出超椭球T-S故障树分析方法,解决区间T-S故障树在进行可靠性分析时,分析结果相对保守的问题;进而,定义凸模型T-S故障树的重要度指标,为找到系统的关键环节提供依据;求解出上级事件的失效可能性、底事件的T-S凸模型重要度和T-S凸模型关键重要度,通过与凸模型布尔逻辑门故障树、T-S故障树进行对比,验证所提方法的可行性。最后,给出了组合导航系统可靠性分析实例。

In order to solve the uncertainty of basic events＇ failure possibilities in T-S fault tree due to poor fault data and complex fault mechanisms, and overcome applicability shortcomings of probability and fuzzy T-S fault tree and Boolean logic gate fault tree, convex model T-S fault tree and importance analysis methods are proposed： Interval T-S fault tree is proposed, which combines interval model with T-S fault tree and utilizes interval model to describe the failure probabilities of basic events as not easy to obtain accurately; On this basis, hyper-ellipsoid T-S fault tree is proposed, which utilizes hyper-ellipsoid model to define the ranges of the uncertain parameters to improve the relatively conservative reliability indices calculated by the interval T-S fault tree method; Then the importance indices of convex model T-S fault tree are presented to provide basis for finding the key link of the system; The failure possibilities of super events and T-S convex model importance and T-S convex model criticality importance of basic events are obtained, and the feasibility of the proposed methods are proved by comparing with convex model Boolean logic gate fault tree and T-S fault tree methods. At last, the proposed convex model T-S fault tree and importance analysis methods are applied to reliability analysis of an integrated navigation system.