Challenge :
Online condition monitoring of machines operating under variable speeds and loads, requires a special attention. Variation in speed or load has an impact on the vibration response, and consequently, this could hide potential faults easily detected in steady regime. Change in shaft speed imposed by the process causes considerable distortion in the vibration spectrum so that the signatures of a given fault become very difficult to identify. Moreover, transient operations could result in a significant vibration amplification despite the non-critical state of the installation -due to natural frequencies crossing-. In fact, this effect could be very harmful for an online condition monitoring system -false alarms- if the latter haven’t been designed to consider such changes in operating parameters.
