THERMAL SPRAY DIAGNOSTICS

• US 20160354796A1
• Filed: 06/03/2016
• Published: 12/08/2016
• Est. Priority Date: 06/04/2015
• Status: Active Grant

• Current Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc), Virginia Tech Intellectual Properties, Inc.
• Original Assignee: Virginia Tech Intellectual Properties, Inc.
• Inventors: Sinatra, Raymond J., Blair, Taylor K., Cybulsky, Michael, Gold, Matthew R., Pickrell, Gary, Batra, Romesh
• Granted Patent: US 10,724,999 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B05B 1/002 designed to reduce the generation or the transmission of noise or to produce a particular sound; associated with noise monitoring means
• CPC Class Codes: B05B 12/006 Pressure or flow rate sensors
• CPC Class Codes: B05B 15/18 for improving resistance to wear, e.g. inserts or coatings; for indicating wear; for handling or replacing worn parts
• CPC Class Codes: B05B 7/16 incorporating means for heating or cooling the material to be sprayed spraying by means of explosions B05B7/0006
• CPC Class Codes: G01N 2291/02425 Liquids in gases, e.g. sprays
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• 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 29/4427 with stored values, e.g. threshold values
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14

Abstract

An example system includes at least one acoustic sensor configured to generate at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes, and a computing device including an acoustic data signal processing module configured to receive the at least one time-dependent acoustic data signal, and transform the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band, and a correlation module configured to determine a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.

Claims

1. A system comprising:

at least one acoustic sensor configured to generate at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes; and

a computing device comprising;

an acoustic data signal processing module configured to;

receive the at least one time-dependent acoustic data signal; and

transform the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band; and

a correlation module configured to determine a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.

2. The system of claim 1, wherein the acoustic data signal processing module is configured to transform the at least one time-dependent acoustic data signal to the frequency-domain spectrum using at least one of a discrete Fourier transform or a fast Fourier transform.

3. The system of claim 1, wherein the correlation module is configured to determine the process attribute by at least:

extracting a plurality of intensities from a selected frequency band of the frequency-domain spectrum, each intensity of the plurality of intensities corresponding to a respective frequency of a plurality of frequencies within the selected frequency band; and

selecting at least one of an intensity of the plurality of intensities or the respective frequency of the plurality of frequencies as the at least one characteristic.

4. The system of claim 1, wherein the at least one characteristic comprises at least one of a peak frequency or a peak intensity.

5. The system of claim 1, wherein the correlation module is further configured to determine the process attribute by at least comparing the at least one characteristic at a first interval of time with the at least one characteristic at a second interval of time.

6. The system of claim 1, wherein the correlation module is further configured to determine the process attribute by at least comparing the at least one characteristic at a third interval of time with a predetermined characteristic value range.

7. The system of claim 1, wherein the correlation module is further configured to determine the process attribute by at least comparing the at least one characteristic at a fourth interval of time with a respective known characteristic of a known frequency-domain spectrum.

8. The system of claim 1, wherein the process attribute of the plurality of process attributes comprises at least one of:

a process parameter comprising at least one of a temperature, a pressure, a mass flow rate, a volumetric flow rate, a molecular flow rate, a molar flow rate, a composition or a concentration, of a flowstream;

or

a process deviation status comprising at least one of powder pulsing, material feed fluctuation, flow blockage, gas leakage, or a process deviation resulting from incompatibility or wear of a system component.

9. The system of claim 8, wherein the system component comprises at least one of a thermal spray gun, a plasma electrode, a powder port, or a material inlet port.

10. The system of claim 1, wherein the computing device further comprises an output device configured to output a representation of at least one of the at least one time-dependent acoustic data signal, the frequency-domain spectrum, the at least one characteristic of the frequency-domain spectrum, or the process attribute of which the at least one characteristic is indicative.

11. The system of claim 1, wherein the process comprises at least one of spraying, gas combustion, electrical arcing, plasma generation, flow shock, powder transport, or mechanical motion.

12. A method comprising:

receiving, by a computing device, from at least one acoustic sensor, at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes;

transforming, by the computing device, the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band; and

determining, by the computing device, a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.

13. The method of claim 12, wherein transforming the at least one time-dependent acoustic data signal into the frequency-domain spectrum comprises performing at least one of a discrete Fourier transform or a fast Fourier transform.

14. The method of claim 12, wherein determining the process attribute comprises:

extracting a plurality of intensities from a selected frequency band of the frequency-domain spectrum, each intensity of the plurality of intensities corresponding to a respective frequency of a plurality of frequencies within the selected frequency band; and

selecting at least one of an intensity of the plurality of intensities or the respective frequency of the plurality of frequencies as the at least one characteristic.

15. The method of claim 12, wherein the at least one characteristic comprises at least one of a peak frequency or a peak intensity.

16. The method of claim 12, wherein determining the process attribute further comprises comparing the at least one characteristic at a first interval of time with the at least one characteristic at a second interval of time.

17. The method of claim 12, wherein determining the process attribute further comprises comparing the at least one characteristic at a third interval of time with a respective predetermined characteristic value range.

18. The method of claim 12, wherein determining the process attribute further comprises comparing the at least one characteristic at a fourth interval of time with a respective known characteristic of a known frequency-domain spectrum.

19. The method of claim 12, wherein the process attribute of the plurality of process attributes comprises at least one of:

a process parameter comprising a temperature, a pressure, a mass flow rate, a volumetric flow rate, a molecular flow rate, a molar flow rate, or a concentration, of a flowstream;

or

a process deviation status comprising at least one of powder pulsing, material feed fluctuation, flow blockage, gas leakage, or a process deviation resulting from incompatibility or wear of a system component.

20. A computer readable storage medium comprising instructions that, when executed, cause at least one processor to:

receive, from at least one acoustic sensor, at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes;

transform the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band; and

determine a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.