论文部分内容阅读
针对将可靠性框图(RBD)转化为等价三层贝叶斯网络(BN)时存在的与RBD结构差异大的缺陷及组合爆炸问题,提出了一种将RBD转化为同构三态BN网络的方法.通过将失效分为“物理故障”和“正常却不工作”两种模式,提出将网络节点转换为包含正常状态以及上述两种失效模式的三态节点,取代仅有正常和失效两种模式的传统模型节点.并在此基础上深入分析了三态BN模型节点的条件概率表(CPT)设置方法.最后建立了与某型飞机航行任务RBD等价的三层BN模型和同构三态BN模型,并对两种BN进行分析计算.理论和实例分析均表明,本文建立的三态BN不仅与原RBD拓扑结构相同,且能够有效解决三层BN存在的组合爆炸问题,可成为系统可靠性分析的有效手段.
Aiming at the defect that the RBD structure is different from the RBD structure and the combinatorial explosion problem when transforming the RBD into the equivalent three-layer Bayesian network (BN), a new method is proposed to transform the RBD into a homogeneous three-state BN network By dividing the failure into two modes, “physical fault” and “normal but not working.” It is proposed to transform the network node into a three-state node containing the normal state and the above two failure modes instead of the only Normal and invalid mode nodes, and based on this, the condition probability table (CPT) setting method for three-state BN model nodes is deeply analyzed.Finally, a three-layer BN Model and isomorphic three-state BN model, and the two kinds of BN are analyzed and calculated.Theoretical and case analysis show that the three-state BN established in this paper is not only the same as the original RBD topology, but also can effectively solve the combined explosion The problem can be an effective means of system reliability analysis.