考虑共因故障的系统组成单元故障严重性测度模型

Measurement Model of Fault Severity for Components Considering Common Cause Faults

针对共因故障影响下的系统组成单元故障严重性测度问题,借助合作博弈思想,将系统组成单元看作是博弈的参与主体,将共因部件组定义为博弈过程中形成的联盟,构建了考虑共因故障的系统组成单元故障严重性Shapley值测度模型。首先,针对传统故障严重等级测度的不足,建立了故障严重等级非线性转换函数;其次根据共因故障特征提出了其联合严重性测度方法;然后根据共因部件组的形成概率以及系统组成单元对不同共因部件组联合严重度的边际贡献,求解出了共因故障影响下的系统组成单元故障修正严重度;最后结合某型号数控机床主轴系统的案例研究,探讨了不同非线性转换以及是否考虑共因故障对系统组成单元故障严重性测度的影响,表明了所提方法的可行性。

To measure the severity of component’s single faults with the consideration of common cause faults, the components were taken as the participants and the alliances were considered as the common cause component groups by using cooperative game theory, a Shapley value measurement model of component fault severity was proposed considering common cause faults. Firstly, a nonlinear transformation function of fault severity level was established, aiming to improve the grade-based fault severity measurements. Secondly, a method of measuring the joint severity of common cause failures was developed according to the characteristics of common cause faults, and then the expected contribution of each components to the all common cause fault severity was calculated with the determination of the types and numbers of common cause component groups. At last, a case of spindle system in CNC machine was presented to demonstrate the effectiveness of the proposed model. The influences of nonlinear transformation function as well as the common cause faults on the fault severity measurements were also investigated in the case.