Fault Diagnosis Method for Analog Circuits Based on Matrix Perturbation Analysis

To integrate the fault detection, fault localization and parameter identification of analog circuits in one system and reduce the cost and facilitate the engineering implementation of fault diagnosis, an fault diagnosis and parameter identification method for analog circuits based on matrix perturbation theory was proposed. First, curve fitting for the sampled time series of the faulty circuit was conducted, and the phase deviation of the circuit was treated as one fault signature . Then, a matrix was built using the sampled time series, and the trace of this matrix was used as the other fault signature. Finally, the phase deviation and trace were used as joint fault signatures, and the fault diagnosis model was established according to the correspondence between the changes of the fault signatures and the fault device parameter variations. The experimental results of two international standard circuits show that the accuracy of fault location ranges from 98.5% to 100% and the error of fault parameter identification is in the range of -1.2% to 1.72%.