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基于分数阶Fourier变换(FRFT)时-频分析理论的特点,构造信号验证了FRFT能解除时频偶合的特性.在此基础上,采用FRFT对某涡轴发动机典型的喘振试验数据进行喘振特征信号提取,然后基于有效特征信号的FRFT功率谱进行喘振瞬时频率的估计.结果表明:利用旋转角与喘振特征相匹配分数阶Fourier变换的能量聚集特性,能有效提取发动机喘振特征信号,并能利用FRFT结果,采用最优信号提取旋转角下的FRFT功率谱进行喘振瞬时频率的估计.
Based on the characteristics of fractional Fourier Transform (FRFT) time-frequency analysis theory, the signal is verified by FRFT to eliminate the characteristic of time-frequency coupling.On the basis of this, FRFT is used to surge the typical surge test data of a turboshaft engine Then the instantaneous frequency of the surge is estimated based on the FRFT power spectrum of the effective characteristic signal.The results show that the energy accumulation characteristic of the fractional Fourier transform matching the surge feature can effectively extract the characteristic signal of the surge of the engine , And can use the FRFT result to extract the instantaneous frequency of surge by using the best signal to extract the FRFT power spectrum under the rotation angle.