An impulse-response extracting method from the modulated signal in a roller bearing

In this paper, a signal processing method is proposed to derive the impulse responses of the defect impacts for a roller bearing, and is carried out in two steps. First, the envelope detection for the vibration signal with amplitude modulation is implemented through the linear least square analysis under the assumption of a stepwise function for the envelope signal. Secondly, the signal processing of impulse-response enhancement is applied to eliminate the sidebands around the defect frequencies. The impulse responses of the defect impacts could be derived and the sidebands in the impulse-response spectrum could be theoretically eliminated. Accordingly, the spectrum would be helpful to apply in the bearing defect diagnosis, especially under the condition of non-uniform loading. From the theoretical analysis and the experimental studies, it is shown that the proposed signal processing method could effectively derive the impact responses of the defects impacts for a roller bearing system and the sidebands in the impulse-response spectrum could be reduced or even eliminated.