Order Bispectrum Based Gearbox Fault Diagnosis During Speed-up Process

Varying speed machinery faults detection is more difficult due to non-stationary vibration. Therefore, most conventional signal processing method based on time invariant carried out in constant time interval are frequently unable to provide meaningful results. In order to process the non-stationary vibration signals such as speed up or speed down vibration signals effectively, the order bispectrum analysis technique is presented. This new method combines computed order tracking technique with bispectrum analysis. Firstly, the vibration signal is sampled at constant time increments and then uses software to resample the data at constant angle increments. Therefore, the time domain transient signal is converted into angle domain stationary one. In the end, the resampled signals are processed by bispectrum analysis method. The experimental results show that order bispectrum analysis can effectively diagnosis the faults of the gear crack