Design of an impulse wavelet for structural defect identification

This paper presents the design of an impulse wavelet for structural defect diagnosis. Specifically, the impulse response measured on a rolling bearing has been used as the basis to formulate a scaling function that satisfies the dilation equation, which is generally provided in standard base wavelets. The scaling function is subsequently used to construct a base wavelet (i.e., an impulse wavelet) for analyzing vibration signals measured on the bearing. Because of the inherent association of the impulse wavelet with the bearing being monitored, it is shown to provide a physically more meaningful method for extracting defect-induced impulsive features embedded in the bearing vibration signals than some of the standard wavelets reported in the literature. Evaluation using sensor data obtained on an experimental test bed confirmed the conclusion.