Abstract: A new method for run-up or coast down vibration signal order tracking filtering of rotating machinery based on instantaneous frequency estimation and zero-phase distortion digital filtering is proposed. In contrast with traditional methods of order tracking filtering, this method includes some advantages. For example, tacho and hardware order filter are not employed to do order tracking filtering and no frequency shift to original sampling data, etc. The principles and algorithms of the method are detailed discussed. A tip to restrain the boundary effect, which caused by digital filter is introduced, the data fragments with overlap, in data fragment filtering. Tests testified the validity of the method.

Key words: Instantaneous frequency estimation, Order tracking filtering, Rotating machinery, Zero-phase distortion filtering