A two-step method using Duffing oscillator and stochastic resonance to detect mechanical faults

Abstract

Stochastic resonance (SR) method can be applied to enhance the signal-to-noise ratio (SNR) of a system output using the unavoidable environmental noise. However, the robustness of SR and the corresponding parameters selection are not agreeable. This paper develops a two-step approach to detect faults in bearings. The first step is done by applying the Duffing oscillator to reveal the weak periodic signals and hence the judgment of existence of faults in mechanical systems. SR is then employed in the second step using Duffing equation as the bistable system. Two barrier parameters in the Duffing equation based bistable system in the second step are obtained using an artificial bee colony (ABC) algorithm. The comparison study between the present two-step method and traditional SR is performed by a numerical simulation signal of cosine function with colored noise. The fault detection results show that the presented method is favored to detect and diagnose rolling bearing fault from a strong noise environment.