| Rolling bearings are the most common and widely used in the operation of rotary machinery and equipment, and the quality of their operation will affect the working conditions of the whole machinery and equipment. However, with the time growing, the bearing will be in the course of the work of varying degrees of damage. It is important to extract the characteristics of the bearing fault signal in these rotary machinery and equipment systems and make an assessment of its damage. Therefore, it is of great significance to study the amplitude estimation of weak signal based on stochastic resonance.Based on the previous research, this paper studies the amplitude estimation of weak signal in stochastic resonance. The main work of the paper is as follows:Firstly, the theory of stochastic resonance and signal to noise ratio to evaluate bitable stochastic resonance systems and Scale-transformation theory are presented and with these basis the deficiency of current cosine fitting algorithm is analyzed.Secondly, the main reason of the rolling bearing faults, the calculation formula of characteristic frequency and the SPM method of rolling bearing fault diagnosis are presented. And then mainly introduced the experimental platform of data sampling.Thirdly, with the nonlinear behavior of stochastic resonance explained by the dynamics, the influence of the amplitude of the input signal, the noise intensity and two kinds of adjustment parameter modes is analyzed on the output amplitude.Finally, a new method based on mathematical morphology is proposed to adjust the adaptive cosine fitting parameter. And based on this method the simulations of Matlab and the data of the experimental platform both show that the method is superior to the traditional cosine fitting algorithm. |
