Application Of Wavelet Neural Network In Fault Diagnosis Of Analog Filter Circuit

With the consistent expansion of integrated scale of electronic components, more and more attentions had attracted for analog circuit diagnosis. Although some important conclusions were used to the fault diagnosis, it is rare to be put into practice especially the ultra large-scale analog. Currently, the research and application for the neural network and wavelet transformation theory has become a hot spot in the field of fault diagnosis. The main purpose of this article is to explore a new method to diagnose the circuit of low order analog filters, the new diagnostic method is combining analog circuit diagnosis with that of wavelet and artificial neural network.Firstly, research’s situation for the analog circuit fault diagnosis is summarized, and the elementary theory of neural network is investigated, because of fault knowledge acquisition for neural network construction, the methods of limited effective sampling and wavelet analysis are adopted for fault knowledge acquisition. We discussed loose ways of the wavelet analysis and the neural network in the analog circuit fault diagnosis on the basis of the Back Propagation neural network. The wavelet has good localization nature in the time and frequency domain, the fault voltage signal is pretreated with the wavelet transformation before it as the input information for neural network this paper, the process can reduce the input nodes of the neural network. In addition, the detailed process of fault diagnosis for analog circuit used wavelet neural networks was introduced, according to the process of fault diagnosis, a band-stop analog filter was choose as example to diagnose. Finally, simulation and experiment results show that compared to BP neural network, BP wavelet neural network has faster convergence, and the feasibility and applicability of this method is.In this paper, some important results are obtained by simlulation and experiment, but there is also some difference from the practical application for the circuit of low order analog filter, and there is other something should be studied in the future.