A comparison between two conventional order tracking techniques in rotating machine diagnostics

Conventional rotating machine vibration monitoring techniques are based on the assumption that changes in the measured structural response are caused by deterioration in the condition of the rotating machine. However, due to variations of the rotational speed, the measured signal many be non-stationary and difficult to interpret. For this reason, the order tracking technique is introduced to identify non-stationary vibration data and to a large extent exclude the influences of varying rotational speed. In recent years, different order tracking techniques have been developed in the context of condition monitoring rotating machines. Each of these techniques has their own pros and cons in analyzing rotating machinery vibration signals. This, however, presents difficulties for the analyst in choosing and applying proper order tracking methods. In this paper, two widely researched order tracking techniques, computed order tracking and Vold-Kalman filter order tracking, are extensively discussed and compared in their abilities and limitations which include the form of the results, issues with respect to practical application procedures, computational effort, etc. The paper is useful for the selection of appropriate order tracking methods and efficient application of the techniques in rotating machine fault diagnostics.