A novel energy demodulation method using B-spline approximation for bearing fault detection

The vibration fault signal recorded from a faulty bearing is generally non-stationary in nature and the envelope of such a signal is usually time-varying. This may bring challenges to bearing fault detection. To overcome such difficulties, a novel energy demodulation technique is proposed in this work, which first interpolates the raw signals with nonuniform B-spline approximation and then utilizes an energy demodulation tool based on an enhanced energy measure called envelope-derivative operator (EDO). The B-spline approximation and the EDO are integrated into a new energy operator for extracting the fault signatures. The B-spline EDO enjoys high time resolution and performs well in the case of strong noise. The superiority of the spline-based EDO in dealing with strong noise is demonstrated by simulation and real experiments.