关键词: 精确重构, 快速傅里叶变换, 频谱校正, 误差评价, 阈值

Abstract: A faulty rotor system vibration acceleration signal integration method based on precise information reconstruction is proposed in this paper by summarizing the advantages and disadvantages of current integration method both in time domain and frequency domain. This method utilizes the characteristic structure of the faulty rotor system vibration signal, which is mainly composed of the rotational frequency and its superharmonic and/or subharmonic frequency components. The fast Fourier transform is performed to the acceleration signal to get its spectrum, then the characteristic frequency components are searched. Comparing the amplitudes of all the extracted components with a threshold set by SNR. The components, whose amplitudes are below the threshold, will be considered as noise components and will be discarded and only those whose amplitudes are above the threshold will be reserved. The high-accuracy spectrum correction is then made with those components reserved to get the precise information, including frequency, amplitude and phase information, needed for the integration and signal reconstruction. The velocity signal and displacement signal are therefore reconstructed with the precise information of all the reserved components. Precise Information Reconstruction is excellent at removing the broadband noise. The reliability and effectiveness of the proposed method are testified by the simulation analysis and the application examples.

Key words: Error evaluation, Fast Fourier transform, Precise information reconstruction, Spectrum correction, Threshold