基于多项式调频小波变换旋转机械转速信号提取

Extraction of Rotating Machinery Speed Signal Based on Polynomial Frequency Modulation Wavelet Transform Method

针对旋转机械振动测试中可能出现的转速信号缺失问题,采用多项式调频小波变换提取振动基频信号,利用转子振动基频信号与转速存在正比的关系获取转速信号。根据解析信号瞬时频率构造多项式变换核函数,采用最小二乘法拟合瞬时频率检峰脊线,以瞬时频率脊线平均误差为优化目标迭代更新多项式变换核参数,最终获得集中度较高的转子振动基频信号瞬时频率。将该方法应用于实际轴承转子实验台转速信号提取,得到在升速与降速过程中转速提取的平均误差分别为0.018与0.012,验证了该方法的有效性。

Aiming at the problem of missing speed signal in the vibration test of rotating machinery,it is proposed to use polynomial frequency modulation wavelet transform to extract the vibration fundamental frequency signal.The rotor vibration fundamental frequency signal has a proportional relationship to the speed for obtaining the speed signal.According to the instantaneous frequency of the analytical signal,a polynomial transformation kernel function was constructed.The least square method was used to fit the instantaneous frequency peak detection ridge.The average error of the instantaneous frequency ridge was used as the optimization target to iteratively update the polynomial transformation kernel parameters.The method was applied to the speed signal extraction of the actual bearing rotor experiment table,and the average error of speed extraction during the speed-up and speed-down process is 0.018 and 0.012 respectively.The proposed method is verified to be effective.