Abstract
Hydraulic pump performance monitoring methods that can detect failures by using the outlet pressure signals of the pump are investigated. Two faults diagnosis methods, namely conventional spectral analysis method based on FFT and wavelet based multi-resolution analysis method, are introduced and their efficiency and reliability are discussed. The performance of both diagnoses methods were evaluated based on simulation results and experimental results. Validation results obtained from using both methods in analyzing the same sets of data indicated that the wavelet transform based fault diagnosis method showed a more sensitive and robust detecting results for all three tested pump faults than that obtained from a spectrum analyses approach.