A Method of Fault Localization within the Blind Spot using the Hybridization between TDR and Wavelet Transform

The blind spot has been an important issue for fault location/diagnosis methods, especially reflectometry. In this paper, a time domain reflectometry (TDR) based on a multi-level wavelet analysis is proposed to accurately localize a fault within a blind spot. The proposed method consists of a parallel fault scanning process which depends on the wavelet decomposition level, (1) time cross-correlation and (2) coefficient feature-based pattern matching. To locate a fault within a wire, the pattern of the TDR reference signal is decomposed to an approximation (low pass) and a detail (high pass) coefficient through a wavelet multi-level analysis. For the low-level wavelet decomposition, the smoothing spline fitted decomposed signal is cross-correlated to detect possible fault locations by comparing the reference signal and the reflected signal. For high-level wavelet decomposed data points, coefficient features are matched to specify the exact location of the fault. In fault scenarios using automotive wires, the experimental results of the fault location and velocity of propagation estimation demonstrates the effectiveness of the proposed method.