The application of stochastic resonance theory for early detecting rub-impact fault of rotor system

In order to catch the characteristic signal of mechanical faults as early and accurately as possible, this paper introduces a new method to detect weak useful signal buried in noise. This method is based on stochastic resonance (SR) theory. First, its principle and property are simply illustrated. Then, the detecting model is given and simulated data are analysed by the model in detail. At last, the model is applied to detect the weak frequency component signals characterising the inception of rub-impact fault of rotor system. The result shows that this method is simple, robust and reliable. The weak sinusoid-like signal of lower signal-to-noise ratio can be reliably extracted from heavy noise. The detection approach of weak signal based on SR indicates promising future for mechanical fault diagnosis. (C) 2003 Published by Elsevier Science Ltd.