Blind instantaneous rotational speed extraction from vibration signals of rotating machines under non-stationary operating conditions

摘要

Order tracking (OT) is one the most used techniques for vibration analysis from rotating machinery under variable speed or load. Yet, the necessity of shaft speed measurement or a priori knowledge about the machine speed turns difficult the extraction of order components. In consequence, in this paper we propose a blind instantaneous rotational speed extraction algorithm, which requires only the information associated to maximum machine speed. The algorithm is based on the velocity synchronous discrete Fourier transform and the assumption that an angle-order map is highly stationary. In order to measure the stationarity of angle-order map, two measures based on variability such as kurtosis and principal component analysis are used. Proposed algorithm is tested in a numerical and a laboratory experiment, and allows identifying with high accuracy the shaft speed.