Abstract: Based on analyzing the advantages and disadvantages of measuring impact signals with kurtosis index and correlation coefficient respectively, the weighted kurtosis index is constructed to make much of the advantages of the both and compensate for their disadvantages. The impact signal adaptive detecting method, combining the constructed index with the scale transformation stochastic resonance, is applied to the simulation of impact signal and the detection of engineering faint impact signals. The results show that the presented method raises the signal-to-noise ratio, and avoids peak leaking phenomenon. Furthermore, because it is independent of stochastic resonance, the present index can be a reference to other adaptive impact signal detecting methods.

Key words: Adaptive, Impact signal, Stochastic resonance, Weighted kurtosis index