An order spectrum based selection method to Vold-Kalman filter bandwidth

Vold-Kalman filter order tracking has attracted increasing attentions of researchers and engineers in condition that the monitoring rotating machines are under non-stationary operational working conditions. Its successful application depends upon the choice of Vold-Kalman filter bandwidth, however nowadays the selection of filter bandwidth is largely relayed on empirical method and sometimes filter bandwidth is selected in an arbitrary fashion. The accuracy and consistency of Vold-Kalman filtering results could not be ensured. Thus, the selection of a Vold-Kalman filter bandwidth becomes a barrier for a proper application of the method. In this paper, an order spectrum based selection process of Vold-Kalman filter bandwidth is proposed. The method considers and makes full use of the relationship between order spectrum and Vold-Kalman filtering result so that an optimal Vold-Kalman filter bandwidth could be chosen and a controlled accuracy of Vold-Kalman filtering result could be obtained. Then, the method is applied to an experimental planetary gearbox system, the characteristic planetary sun gear fault order is being tracked and the proposed filter bandwidth selection process is demonstrated.