模拟电路故障重叠诊断方法研究

Study on the faults overlap diagnosis method in analog circuit

在实际的模拟电路中,电路故障种类很多,但是测试节点的数目是有限的,导致了不同的故障类之间可能存在重叠现象。对于故障重叠问题,采用常规的马氏距离诊断方法,误诊率会很高。阐述了误诊对后期电路改善的严重后果,说明通过降低故障分辨率提高故障诊断正确率是有意义的,提出在进行故障判定时不仅仅考虑最优值还要考虑最优与次优的优劣程度,结合马氏距离故障诊断方法距离进行具体说明,最后对具体电路进行分析,验证了本文的有效性。

There are many kinds of faults in the actual analog circuits. And the limited number of test nodes results in a possible overlap between the different fault classes. For the fault overlap, the usage of conventional diagnostic methods based on Mahalanobis distance makes the high misdiagnosis rate. This paper describes the serious consequences of misdi- agnosis for late circuit improvement, and it is significant to enhance the accuracy of fault diagnosis by reducing the faults resolution. It is proposed that not only the optimal value hut also the degree of optimization and inferior between the opti- mal and suboptimal. The fault diagnosis based on Mahalanobis distance is combined to explain it concretely. Finally, the analysis of the specific circuit is done to verify the validity of the method in this article.