On electronic equipment fault diagnosis using least squares wavelet support vector machines

A systematic approach for fault diagnosis of analog circuits based on least squares wavelet support vector machines and wavelet lifting transform is presented, and is used in the scout radar electronic equipment. Firstly, output voltage signals under faulty conditions are obtained from analog circuits test points and noise is removed from signals with wavelet lifting transform. Then wavelet coefficients of output voltage signals are gained by wavelet lifting decomposition, and faulty feature vectors are extracted from the coefficients. After training the least squares wavelet support vector machines by faulty feature vectors, the least squares wavelet support vector machines model of the circuit fault diagnosis system is built. The simulation result shows the fault diagnosis method of the analog circuits with wavelet lifting transform and least squares wavelet support vector machines is effective.