基于灵敏度序列的非线性模拟电路故障诊断

Fault Diagnosis of Non-Linear Analog Circuits Based on Sensitivity Sequence

对在非线性模拟电路中采用基于灵敏度序列的故障诊断方法进行了研究。针对非线性参数特性,首先采用分段线性叠代方法构建元件的线性模型,在被测电路中采用戴维南和诺顿定理等效替换;而后分段进行测前仿真,构造故障字典。采用分段线性叠代的方法,巧妙地构建了非线性元件的分析模型,避免了求解繁复的非线性代数方程或非线性微分方程。通过对两种等效替代模型进行分析和比较,指出各自的适用范围。在分段线性化后,引入工作域分析策略,简化了含多个非线性元件电路的测前分析。理论分析和相关实验为研究非线性电路的测试与故障诊断提供了新的方法。

Method for fault diagnosis of non-linear analog circuits based on sensitivity sequence was studied.In this work,non-linear parameter curve was separated by PWL（piece wise linear）models and non-linear devices were replaced by Thevenin＇s or Norton＇s equivalent circuits.And the fault dictionary was formed by stimulations before test.Compared to non-linear algebra and differential equation,the PWL model is more compact and efficient.Differences of Thevenin＇s or Norton＇s equivalent models and their application were pointed out.Both theoretial ana-lysis and experimental results show that the method is feasible,and it provides a new strategy for test and fault diagnosis of non-linear circuits.