多稳态随机共振模型下滚动轴承弱异常信号检测方法

Weak abnormal signal detection method of rolling bearing based on multistable stochastic resonance model

摘要:

弱异常信号对应滚动轴承的早期损伤,其故障特征较为微弱容易被外部噪声掩盖,若无法检测出这些信号可能造成故障损伤的持续扩展。对此,提出多稳态随机共振模型下的滚动轴承弱异常信号检测方法。首先,利用郎之万方程式描述变尺度随机共振,以求解多稳态势函数,完成多稳态随机共振模型的设计。在此基础上,分别从小频率、大频率两方面,研究滚动轴承弱异常信号的共振特性,实现基于多稳态随机共振模型的轴承弱异常信号分析。最后,根据滚动轴承基本结构在弱异常表现下的失效作用,估算弱异常特征频率,并利用振动信号完成检测,实现滚动轴承弱异常信号检测方法的设计。实验结果表明,在信噪比低于-15dB的情况下,该方法依然能够提取出滚动轴承的故障特征频率,且检测准确率高于90%,解决了弱异常信号容易被外部噪声掩盖的问题,能够避免滚动轴承早期故障损伤的持续扩展。

Abstract:

Weak abnormal signals correspond to early damage of rolling bearings, and their fault characteristics are relatively weak and easily masked by external noise. If these signals cannot be detected, it may cause the continuous expansion of fault damage. A method for detecting weak abnormal signals in rolling bearings under a multi steady state stochastic resonance model is proposed. Firstly, the Langzhiwan equation is used to describe the variable scale stochastic resonance, in order to solve the multi steady state potential function and complete the design of the multi steady state stochastic resonance model. On this basis, the resonance characteristics of weak abnormal signals in rolling bearings are studied from both low frequency and high frequency perspectives, and the analysis of weak abnormal signals in bearings based on a multi steady state stochastic resonance model is achieved. Finally, based on the failure effect of the basic structure of rolling bearings under weak abnormal behavior, the weak abnormal characteristic frequency is estimated, and the vibration signal is used to complete the detection, realizing the design of a weak abnormal signal detection method for rolling bearings. The experimental results show that even when the signal-to-noise ratio is below -15dB, this method can still extract the fault characteristic frequency of rolling bearings, and the detection accuracy is higher than 90%, solving the problem of weak abnormal signals being easily masked by external noise and avoiding the continuous expansion of early fault damage of rolling bearings.