On the Use of Stochastic Resonance in Mechanical Fault Signal Detection

This chapter focuses on the application of stochastic resonance (SR) in mechanical fault signal detection. SR is a nonlinear effect that is now widely used in weak signal detection under heavy noise circumstances. In order to extract characteristic fault signal of the dynamic mechanical components, SR normalized scale transform is presented and a circuit module is designed based on parameter-tuning bistable SR. Weak signal detection based on stochastic resonance (SR) can hardly succeed when noise intensity exceeds the optimal value of SR. Therefore, a signal detection model based on combination effect of colored noise SR and parallel bistable SR array, which is called multi-scale bistable stochastic resonance array, has been constructed. Based on the enhancement effect of the constructed model and the normalized scale transformation, weak signal detection method has been proposed. The effectiveness of these methods are confirmed and replicated by numerical simulations. Applications of bearing fault diagnosis show the enhanced detecting effects of the proposed methods.