分数阶傅立叶变换(FRFT)是经典傅立叶变换的广义形式,它克服了经典傅立叶变换在故障特征提取中存在不足,可同时从时间域和频率域(或空间域)揭示信号特征.论述了分数阶Fourier变换的定义、特点和算法,并进行实验研究.实验结果表明,只要选择合适的分数阶数,可取得比传统傅立叶变换更好的效果.
The fractional Fourier transform(FRFT),which is a version of generalized common Fourier transform(FFT) can overcome the incomplete of FFT in feature extraction of fault signal.FRFT also reveals the features of signal from time and frequency simultaneously.The definition,feature and algorithm of the FRFT is introduced.Then the method is applied to the diagnosis of rolling bearing.The result shows that the fractional Fourier transform can give better analysis in appropriate fractional order.