A method and related system for measuring rotor unbalance comprises rotating a
rotor about an axis at a range of rotating speeds; generating a reference signal
indicative of the instantaneous rotational frequency of the rotor; detecting the
vibration of the rotor while the rotator is rotating, and generating a vibration
signal; filtering the vibration signal, using the reference signal, to provide
a synchronous vibration signal having a frequency equal to the instantaneous rotational
frequency of the rotor; recording a vibration vector, the vibration vector comprising
amplitude and phase values for the synchronous vibration signal; and measuring
rotor unbalance based upon the vibration vector. Measurement accuracy can be improved
by recording vibration vectors for a plurality of rotations of the rotor, and determining
an average vibration vector. Methods and systems for detecting a rotor anomaly
are also disclosed.
