US 12,146,808 B2
Optical acoustic sensing system and method
Paul Wilson, Pinjarra Hills (AU); Timothy Brooks, Pinjarra Hills (AU); Long Giang, Pinjarra Hills (AU); Karsten Hoehn, Pinjarra Hills (AU); and Michael Lofgren, Pinjarra Hills (AU)
Assigned to CMTE DEVELOPMENT LIMITED, Pinjarra Hills (AU)
Appl. No. 16/488,202
Filed by CMTE DEVELOPMENT LIMITED, Pinjarra Hills (AU)
PCT Filed Feb. 22, 2018, PCT No. PCT/AU2018/050144
§ 371(c)(1), (2) Date Aug. 22, 2019,
PCT Pub. No. WO2018/152575, PCT Pub. Date Aug. 30, 2018.
Claims priority of application No. 2017900583 (AU), filed on Feb. 22, 2017.
Prior Publication US 2020/0064226 A1, Feb. 27, 2020
Int. Cl. G01M 13/045 (2019.01); G01H 9/00 (2006.01)
CPC G01M 13/045 (2013.01) [G01H 9/004 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method of measuring the state or condition of a plurality of spatially spaced apart machine parts subject to wear and emitting an acoustic signature, the method including the steps of:
(a) optically sensing acoustic properties of the plurality of spatially spaced apart machine parts subject to wear, and deriving sensed signals there from,
(b) dividing the sensed signals into a first series of corresponding spatial segments along the plurality of spaced apart machine parts and, for each spatial segment, dividing the sensed signal into a temporal segment recording the acoustic properties for the spatial segment over an extended time period;
(c) dividing each temporal segment into a series of sub-segments and frequency domain transforming the sub-segments into corresponding frequency domain sub-segments;
(d) combining the frequency domain sub-segments within a spatial segment, to produce a corresponding lower noise level combined frequency domain sub segment;
(e) determining a fundamental operating frequency of at least one of the machine parts from the emitted acoustic signature from the combined frequency domain sub segment, and determining the associated harmonics of the fundamental frequency;
(f) removing the fundamental frequency and associated harmonics from the combined frequency domain subsegment to produce a modified combined frequency domain sub segment; and
(g) determining, from the modified combined frequency domain sub segment for a spatial segment, a measure of the state or condition of a corresponding machine part the measure including at least one of:
(i) the magnitude of frequency spikes in the modified combined frequency domain sub segment below 100 hz and not one of the fundamental frequency or harmonic frequencies, indicating the state of wear of machine part surfaces;
(ii) the magnitude of a series of any frequency spikes between 50 hz and 250 hz, in the modified combined frequency domain sub segment and not a fundamental frequency or harmonic frequency, indicative of mid-life machine part wear; or
(iii) the magnitude of any series of frequency spikes in the modified combined frequency domain sub segment above 250 hz, and not a fundamental or harmonic frequency, indicative of late stage machine part wear.