An optimized short-time fractional fourier transform and its application in signal extraction
Jili Wu, Xiang Yu, Buzhao Niu, Zhiqiang Zhang, Yuyang Peng · 2025
In fault diagnosis, the modulated signal that can reflect fault characteristics are often related to speed information, and the frequency modulation phenomenon caused by variable speed poses a challenge to feature extraction. In this paper, a short-time fractional fourier transform (STFRFT) time-frequency(TF) analysis method with adaptive window length is proposed to extract fault feature in variable speed signal. In this method, short-time fourier transform (STFT) is first used to obtain a coarser speed curve, followed by principal component analysis (PCA) to obtain a finer speed curve, and the slope of each segment on the fine curve is calculated to solve all the optimal order p, finally FRFT is sequentially used in each segment to filter the component of interest. The simulation and experimental results validate the effectiveness of the method.