混合诊断建模与故障检测率和隔离率算法解析

Hybrid Diagnostic Modeling and Computation of FDR/FIR

摘要:

针对混合诊断建模中故障“有时影响”功能以及故障和功能可靠性数据冲突情况下的故障检测率和故障隔离率计算问题,研究了混合诊断建模与推理规则以及故障和功能可靠性数据冲突处理方法,通过分解故障并扩展故障－测试相关矩阵定义,将故障与功能间不确定性关联转化为确定性关联,归纳了故障和功能可靠性数据冲突处理计算公式,提出了基于扩展故障-测试相关矩阵和分别采用故障模式均分法、故障模式优先法、功能优先法的故障检测率和故障隔离率算法,给出了计算示例,并与eXpress软件运行结果相对照,验证了所提算法的正确性,深化了对eXpress软件功能原理的认识。

Abstract:

Hybrid diagnostic modeling is an extension of diagnostic dependency modeling. In hybrid diagnostic model, the relationship of the failure mode each affected function can be sometimes affects, and function definition is comprised of reliability data. To compute Fault Detection Rate (FDR) and Fault Isolation Rate (FIR) when failure modes sometimes affect functions and there are conflicts between failure modes reliability data and functions reliability data, this paper first studies hybrid diagnostic modeling, hybrid diagnostic inferences and the correlation of failure rates for functions and failure modes, then divides failure modes that sometimes affect functions and extends the definition of fault-test dependency matrix, sums up the computing formulas of failure probability calculation method, proposes the algorithm of FDR/FIR computation with failure mode apportionment, failure mode precedence and functional precedence. The results of the example are same to eXpress running results, so the algorithm of FDR/FIR computation is demonstrated to be correct. The study is helpful to understand the principle of eXpress.