一种改进自适应陷波器在齿轮箱振动信号频率估计中的应用

针对多级齿轮系统振动主动控制所需参考信号的获取问题,设计一种基于变步长无偏平滑梯度算法的二阶IIR自适应陷波器。以实时振动信号为输入信号,通过调整陷波频率实现对齿轮啮合频率的在线估计,并采用自适应改变陷波器迭代步长的方法提高估计速度和精度,仿真验证了该陷波器相比传统自适应陷波器具有更快的估计速度和更小的稳态误差,与FFT和比值校正FFT两种方法比较,所提陷波器对频率变化具有更好的追踪性能;将两个陷波器串联构成级联陷波器组,通过二级齿轮箱的振动加速度信号对两个啮合基频分别进行在线的实时估计。实验结果显示级联陷波器组能快速且准确地估计对应啮合频率,且能实时追踪由于驱动和负载变动导致的啮合频率变化,证明所提方法在实际应用中的有效性。

Application of a modified adaptive notch filter in frequency estimation of gearbox vibration signals

In order to obtain a reference signal for active vibration control of a multi-stage gear system,a second-order IIR adaptive notch filter based on the variable step-size unbiased plain gradient(VSSUPG) algorithm was designed. Taking a real-time vibration signal as an input signal, the online estimation of gear meshing frequency was realized through adjusting notch frequency, and the adaptively changing the notch filter’s iterative step method was used to improve the estimation speed and accuracy. Simulation results showed that the proposed adaptive notch filter has a faster estimation speed and a smaller steady-state error than those of the traditional adaptive notch filter;compared with FFT and ratio-corrected FFT, the proposed filter has a better tracking performance to frequency changes. A cascaded notch filter set was constructed by connecting two adaptive notch filters in series to do online estimation of two meshing fundamental frequencies using vibration acceleration signals of a two-stage gearbox. The test results showed that the cascaded notch filter set can be used to quickly and correctly estimate the corresponding meshing frequencies, track meshing frequency changes in real time due to driving and load changes, and verify the effectiveness of the proposed method in practical application.