Abstract: A method based on the Lissajous figures is put forward in order to solve the defects of fault diagnosis of nonlinear circuits. A Lissajous figure is composed of excitation signals and measurable node signals in the circuit, which can be analyzed by using the curvature energy and feature points of curvature. Then we can get the useful information of Lisasajous figures which will be used to form the fault feature vector. This method has the advantage of combining the information of excitation signals and measurable nodes, and it doesn’t need to analyze the circuit topology. The simulation experiments show that the diagnosis result of the logarithmic amplifying circuit can reach 90 %, which proves that the method has good effect for nonlinear analog circuit fault diagnosis.

Key words:  , Lissajous figure, curvature, curvature energy, fault diagnosis

摘要： 针对非线性电路的故障诊断的难题，提出了一种基于李沙育图形对非线性模拟电路进行故障诊断的方法。通过合成电路的激励信号与可测节点信号的李沙育图形来诊断电路故障。结合曲率弯曲能与曲率特征点可提取李沙育图形的有效信息构成故障特征向量。该方法的优点在于可以充分结合激励信号和可测节点信号的信息，且不需要对电路拓扑结构进行分析。仿真实验结果显示，该方法对对数放大电路的故障诊断率达到90 %以上，具有较好的非线性模拟电路故障诊断效果。

关键词: 李沙育图形, 曲率, 弯曲能, 故障诊断