Patent ID: 7133801

Claim:
A method for monitoring machine faults comprising: (a) determining one or more base vibration features associated with said machine; (b) acquiring time-based vibration data samples from a vibration transducer in physical contact with said machine; (c) determining a machine operating speed estimate for said machine using a continuous vibration model; (d) acquiring vibration data for said machine occurring at said machine operating speed; and (e) determining whether one or more faults exists within said machine based upon a comparison of said base vibration features with said vibration data occurring at said machine operating speed, wherein said determining the machine operating speed estimate further comprises: (a) selecting a discrete range of operating speeds through which to conduct a search; (b) dividing the time-based vibration data sample into a plurality of sub-records of sample lengths; (c) obtaining the coefficients of a digital comb filter based upon P; (d) convoluting the time-based vibration data samples using the digital comb filter in the time-domain; (e) computing the total vibration power and the coherent vibration power, (f) computing a vibration power error function; (g) selecting the optimal P that minimizes the error function by comparing the error functions of all sub-record lengths within said selected discrete range of operating speeds; and (h) estimating and outputting the machine speed RPM based upon said selected optimal P.