Rotating machine speed estimation

Abstract

Embodiments of a process for estimating a rotational speed of a rotating component and a process for estimating an acceptable rotor imbalance of a rotating component are provided herein. The process for estimating the rotational speed of a rotating component for a charging system comprises measuring a vibration signal of the rotating component by means of a sensor; and identifying harmonic train members from a plurality of peaked components of the vibration signal. Further, the process comprises determining a candidate fundamental frequency from the harmonic train members; and determining a derived vibration amplitude value from the vibration signal. This determination involves a filtering of the vibration signal, removing periodic contributions having a high amplitude. A scalar value is then derived from the filtered signal as a derived vibration amplitude value, representing the integrated total vibration amplitude of the filtered signal at the current speed. The process comprises verifying a consistency condition between the derived vibration amplitude value and the candidate fundamental frequency using a predetermined speed-amplitude map, associating speed values with their respective derived vibration amplitude values. For determining an acceptable rotor imbalance, a speed-amplitude map obtained at a time when the imbalance is acceptable is compared to a speed-amplitude map at a later point in time. An offset between the maps may indicate an inacceptable imbalance.