A Study on Additional-signal-enhanced Stochastic Resonance in Detecting Weak Signals

Noise can improve the signal-to-noise ratio of many nonlinear dynamical systems. This "stochastic resonance" (SR) effect occurs in a wide range of physical systems and biological systems, and also occurs in engineering systems in signal processing, communications, and control. Based on the theory of SR for detecting weak signals, a novel approach of detecting weak periodic signal using additional-signal-enhanced SR(ASESR) is presented. This method is analyzed by simulated signal. Through a kind of normalized scale transform, the frequency restriction condition of the signal to be detected is eliminated. The model is applied to detect the weak frequency component signals characterizing the inception of rub-impact fault of rotor system. The result shows that this method is simple and feasible. The weak sinusoid signal of low signal-to-noise ratio can be extracted from heavy noise. The detecting approach indicates a promising prospect for engineering signal detection.