势函数特征参数调节随机共振及动车轴承故障检测研究

Stochastic resonance with adjustable potential function characteristic parameters and its application in EMU bearing fault detection

双稳随机共振的系统参数调节,会使势函数的势垒高度和势阱间距同时发生变化。为了能直观了解势函数特征的变化对双稳随机共振的影响,通过变量代换法实现势函数特征参数(势垒高度参数和势阱间距参数)的解耦,有利于势函数的调节;并提出了基于势函数特征参数调节的随机共振方法,根据Kramers逃逸速率与目标信号频率匹配原则,实现了目标信号的检测;为了克服随机共振对采样频比的要求,将势函数特征参数调节的随机共振与频域信息交换技术相结合,实现了低采样频比信号的检测。所提方法应用于动车转向架轴承故障的检测结果验证了方法的有效性。

Potential function characteristic parameters (PFCPs) including barrier height and potential well spacing are changed simultaneously when system parameters are adjusted in a classical bi-stable stochastic resonance (SR) system. Here, the variable substitution method was used to realize PFCPs being decoupled, which was beneficial to adjusting potential function. Then the SR method based on adjustable PFCPs was proposed, according to the matching principle between Kramers escape rate and target signal frequency, target signal detection was realized. In order to overcome the difficulty of sampling frequency ratio’s high demand for SR, the technique of frequency information exchange (FIE) was introduced and combined with the proposed method to realize signal detection with lower sampling frequency ratio. The detection results for bearing faults of EMU bogie system verified the effectiveness of the proposed method.