模拟电路参数型故障诊断一直是电路与系统无法回避的难题。该文基于被测电路主输出电压信号的时间序列值,建立了一种基于本征值和相位差的模拟电路参数型故障诊断模型。该模型利用故障电路的电压输出时间序列值获取电路的故障相位偏移信息,同时,该模型把电压时间序列变换成一个方阵,并求取该方阵的最大本征值。将故障相位偏移信息和故障最大本征值与通过前期仿真获得的每种器件相对应的无故障最大相位偏移和无故障最大本征值的变化趋势进行比较,实现故障定位和参数辨识。实测实验结果表明:该方法具有定位准确、计算效率高,所需测试点少、参数辨识精度高,易于工程实施等优点。
This paper proposes a new model for parametric fault diagnosis in analog circuits, which is one of the most challenging problems in circuits and systems. This new model is based on the eigenvalue and phase difference from the time series of the output voltage of the circuit under test (CUT). The phase deviation information of the circuit is obtained via the sampling voltage time series. The sampling voltage time series is reorganized to be a matrix, and dominant eigenvalue of this matrix is obtained accordingly. Finally, by comparing the phase deviation and the dominant eigenvalue of the CUT with those of the fault free circuit in absolute relative error criteria, fault location and parameter identification can be accomplished. Experimental results show that the proposed method performs well in both fault location and parameter identification with very few access points and relatively low computation cost, moreover, fault location and parameter identification can be realized simultaneously, which makes it an effective and efficient method for fault diagnosis of analog circuits.