Signal Denoising Method Using AIC-SVD and Its Application to Micro-Vibration in Reaction Wheels.

To suppress noise in signals, a denoising method called AIC-SVD is proposed on the basis of the singular value decomposition (SVD) and the Akaike information criterion (AIC). First, the Hankel matrix is chosen as the trajectory matrix of the signals, and its optimal number of rows and columns is selected according to the maximum energy of the singular values. On the basis of the improved AIC, the valid order of the optimal matrix is determined for the vibration signals mixed with Gaussian white noise and colored noise. Subsequently, the denoised signals are reconstructed by inverse operation of SVD and the averaging method. To verify the effectiveness of AIC-SVD, it is compared with wavelet threshold denoising (WTD) and empirical mode decomposition with Savitzky-Golay filter (EMD-SG). Furthermore, a comprehensive indicator of denoising (CID) is introduced to describe the denoising performance. The results show that the denoising effect of AIC-SVD is significantly better than those of WTD and EMD-SG. On applying AIC-SVD to the micro-vibration signals of reaction wheels, the weak harmonic parameters can be successfully extracted during pre-processing. The proposed method is self-adaptable and robust while avoiding the occurrence of over-denoising.