基于改进马氏距离的模拟电路故障诊断方法

Method for analog circuit fault diagnosis based on improved Mahalanobis distance

提出一种基于改进马氏距离的模拟电路故障诊断方法.根据被测电路的拓扑结构进行可测性分析,利用测试矩阵确定规范模糊组,从而得到单故障假设下的可分潜在故障元件.将马氏距离根据模拟电路的特性作出改进,并应用于模拟电路潜在故障元件的诊断.利用测点特征值的改进马氏距离对潜在元件进行划分,减少可疑故障元件的类别,在诊断分类时达到提高速度的效果.实验表明,所提出的方法对模拟电路软故障诊断速度较快,具有较好的模拟电路故障诊断测试效果.

A method based on improved Mahalanobis distance according to the characteristics of analog circuits is proposed for fault diagnosis. Firstly, the circuit testability is analyzed based on the topology of the test circuit and the ambiguity groups are determined by using test matrix. Then the separable potential faulty components under the assumption of single fault are identified. Finally, improved Mahalanobis distance of the feature values of the test points is applied to classify the suspicious components, resulting in fewer classes and faster speed for fault classifying process. Simulation results show that the proposed method can improve the fault diagnosis rate and is effective for analog circuit fault diagnosis and classification.