Research on standard three-well stochastic resonance system and its application in early bearing fault diagnosis

The theoretical method of stochastic resonance (SR) is helpful for the extraction of mechanical fault signals in the background of strong noise. Therefore, SR has been developed rapidly in the field of mechanical fault diagnosis. In the method of fault diagnosis based on SR, the under-damped tri-stable SR system shows its superiority in performance. However, the disadvantage of this model is that the potential function of the nonlinear system is not standardized enough, which brings inconvenience to the subsequent adjustment of system parameters. In order to solve this problem, this paper proposes a standard three-well underdamped stochastic resonance system. The steady-state probability density and output signal-to-noise ratio of the system are fully studied. Finally, a fault signal detection method based on the standard three-well underdamped stochastic resonance system is proposed, and the feasibility of this method in early fault diagnosis is proved by two different experimental platforms.