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 this paper. By contrast with traditional methods of order tracking filtering, the features of tacholess, no hardware-based tracking filter required and no frequency shift to original sampling data, etc, make it more attractive. The theorems and algorithms of the method are detailed discussed in this paper. The filtering of overlapped data blocks is used to restrain the edge effect, which caused by digital filtering, is also introduced. An actual test example of a motor’s run-up and coast down vibration is introduced to demonstrate the validity of the method.
