A Novel Algorithm for Instantaneous Angular Speed Estimation Based on Vibration Signatures

In the Israel Railways rolling stock, some train cars suffer from damaged bearings of the condenser fans of the A/C system. For these systems, vibration analysis is an effective method for detecting various faults and malfunctions. The diverse methods for processing vibration signals require knowledge of the rotational speed of the machine in question, since in rotating parts, fault events occur at specific angular positions rather than at specific times. For this reason, an accurate estimate of the instantaneous angular speed (IAS) is important for reliable diagnosis. In practice, direct measurement of the rotational speed of the A/C system Israel Railways fleet of train cars is impossible due to regulations and operational constraints.