METHOD, SYSTEM AND COMPUTER PROGRAM FOR THE ACOUSTIC ANALYSIS OF A MACHINE

• US 20160238486A1
• Filed: 10/09/2014
• Published: 08/18/2016
• Est. Priority Date: 10/11/2013
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma (Safran SA)
• Inventors: Bense, William, Lacaille, Jrme, Gerez, Valerio
• Granted Patent: US 10,495,546 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01M 15/12 by monitoring vibrations
• CPC Class Codes: G01M 15/14 Testing gas-turbine engines or jet-propulsion engines
• CPC Class Codes: G01N 2291/2693 Rotor or turbine parts
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/4436 with a reference signal amplitude comparison G01N29/48
• CPC Class Codes: G01N 29/4454 Signal recognition, e.g. specific values or portions, signal events, signatures
• CPC Class Codes: G01N 29/449 Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 29/005 Microphone arrays

Abstract

A method for the acoustic analysis of a machine (M) including the acquisition of at least one acoustic signal supplied by at least one microphone (7) positioned in the machine, characterized in that it comprises the following steps: separation of at least one acoustic signal into a plurality of sound sources, the signal being modelled as a mixture of components, each one corresponding to a sound source; for at least one separated sound source, determination of a characteristic acoustic signature; comparison of at least one characteristic acoustic signature with at least one reference acoustic signature recorded in a reference database (5).

Claims

1-10. -10. (canceled)

11. A method for the acoustic analysis of a machine including a step of acquiring at least one acoustic signal supplied by at least one microphone positioned in the machine, wherein the method further comprises the steps of:

separating of the at least one acquired acoustic signal into a plurality of sound sources, said at least one acquired acoustic signal being modelled as a mixture of components, each one corresponding to a sound source;

for at least one of the separated sound sources, determining a characteristic acoustic signature;

comparing the at least one characteristic acoustic signature with at least one reference acoustic signature recorded in a reference database.

12. The method according to claim 11 in which each reference acoustic signature corresponds to an acoustic signature characteristic of a defect of the machine, said method further including an identification of a defect of the machine when a difference between a characteristic acoustic signature of a separated sound source and the reference acoustic signature characteristic of said defect is below a threshold.

13. The method according to claim 11, further including a step for determining at least one reference acoustic signature which comprises:

an acquisition of at least one reference acoustic signal supplied by at least one microphone positioned in at least one reference machine;

a separation of at least one reference acoustic signal into a plurality of reference sound sources;

for at least one of the separated reference sound sources, a determination of a characteristic acoustic signature;

a recording in the reference database of the characteristic acoustic signature of at least one separated reference sound source.

14. The method according to claim 13 in which at least one reference machine is a defect-free machine, including an identification of a defective operation of the machine when a difference between a characteristic acoustic signature of a separated sound source and an acoustic signature recorded in the reference database is above a threshold.

15. The method according to claim 13 in which at least one reference machine is the same machine as the machine under acoustic analysis considered earlier or a machine of the same type having the same operating history, said method including an identification of a defective operation of the machine when a difference between a fingerprint vector of the machine composed of at least one characteristic acoustic signature of at least one separated sound source and a fingerprint vector composed of at least one acoustic signature recorded in the reference database is above a threshold.

16. The method according to claim 14 in which at least one reference machine includes at least two machines, said method including a calculation of differences between a fingerprint vector of the machine under acoustic analysis composed of at least one characteristic acoustic signature of at least one separated sound source and fingerprint vectors each constituted of at least one acoustic signature recorded in the reference database corresponding to one of the reference machines.

17. The method according to claim 11, in which the determination of a characteristic acoustic signature of a separated sound source includes a plotting of a spectrogram of said separated sound source, an identification of intensity peaks by thresholding of the spectrogram, a calculation of distances between said intensity peaks.

18. The method according to claim 11, in which the separation of at least one acoustic signal into a plurality of sound sources is carried out by computer processing means configured to implement an independent component analysis.

20. A non-transitory computer program product including code instructions for the execution of the steps of the method according to claim 11, when said program is run on a computer.

19. A system for the acoustic analysis of a machine, including means for acquiring at least one acoustic signal supplied by at least one microphone positioned in the machine, and a reference database in which is recorded at least one reference acoustic signature, the system further comprising:

a module for separating sources configured to separate the at least one acoustic signal into a plurality of sound sources, said at least one acoustic signal being modelled as a mixture of components each one corresponding to a sound source;

a module for determining an acoustic signature configured to determine at least one characteristic acoustic signature of at least one of the separated sound source;

a module for comparing acoustic signatures configured to compare at least one characteristic acoustic signature with at least one reference acoustic signature recorded in the reference database.