非线性模拟电路的故障诊断方法

A Fault Diagnosis Method for Non-linear Analog Circuits

为了诊断非线性模拟电路中的故障,提出了一种基于节点电压增量线性相关性原理的诊断方法.通过对非线性元件的分段线性建模,说明故障造成的节点电压增量满足分段线性相关性.以节点电压平面上的折线作为故障特征构造故障字典,以实测工作点到故障特征折线的距离来衡量电路状态与故障特征的符合程度,可以诊断非线性电路中元件参数的软故障和硬故障.实例验证表明,该方法是一种易于计算机实现的实用化方法.

For diagnosing faults in non-linear analog circuits, a fault diagnosis method is proposed based on the principle of linear relativity of node-voltage increments. By piecewise linear-modeling of non-linear elements, the changes in node-voltages caused by faults are shown to be piecewise linearly related. Broken lines in the node-voltage plane are taken as fault character to construct a fault dictionary, and the distance from the test result point to each broken line is calculated to measure the accordance of the circuit status to the fault character. In this way both soft and hard faults in non- linear circuits can be diagnosed. Experimental results indicated that the proposed method is practical to be implemented in computer.