飞机颤振试飞试验信号的广义时频滤波

针对飞机颤振试飞试验信号噪声过大的问题,提出了一种广义时频域滤波算法。算法采用分数阶傅里叶变换对线性扫频激励及其响应信号进行广义时频分析,利用该类信号在分数阶傅里叶域内的聚焦特性,有效提取真实响应信号,达到信噪分离的目的。给出了具体的滤波算法,并将其应用于仿真算例和实际试飞数据,结果表明该方法可显著提高信号的信噪比。

Filtering in Fractional Fourier Domain for Flight Flutter Testing Data

A generalized time-frequency filtering method is presented for noise reduction of flight flutter testing data. The method employs fractional Fourier transform for time-frequency analysis, and then utilizes the local property of linear sweep signal in fractional Fourier domain to separate true signal from noise. A complete procedure for the filtering is presented. Some problems in the implementation of the method for real testing data are highlighted. Finally, the advantage of the filtering method is illustrated by means of simulated and real flight data.