一种振动能级梳状滤波精确计算方法

An Accurate Computation Method of Vibration Level Based on Comb Band-stop Filter

现有的1/3倍频程处理方法都是以测试信号不包含明显干扰为前提,因而在处理带噪声信号时存在一定先天不足。针对现场测量信号中经常存在规律性噪声(噪声线谱呈梳状等间隔分布)的现象,提出了以Fourier核函数为基函数的梳状带阻滤波器与1/3倍频程有机结合来消除规律性噪声对结果影响的方法。该方法能够在频域下直接消除干扰并计算滤波后信号的振动能级,计算量小、精度高。通过对动力装置功率试验中出现规律性噪声的振动信号进行合理修正,重新评估其振级水平,避免了多次重复试验,节约了试验费用。

The existing 1/3 octave spectrum approaches are usually supposed to test signals without interference. Obviously, this strategy is no more effective when confronted with the signals containing band noise. In this paper, aiming at the regular noise interference, such as comb noise, the Fourier kernel function is employed to construct a comb bandstop filter, and further the filter is combined with the 1/3 octave spectrum to remove the effects exerted by noise. The proposed strategy can remove the interference in frequency domain and calculate the filtered vibration level more efficiently and conveniently, compared with the existing approaches. For the vibration signals with regular noise interference in the power test of a propulsion system, proper revision and consequent reevaluation can avoid repeated tests and save test costs.