1 / 31

Non contact acquisition of sonic emissions of bearings

Non contact acquisition of sonic emissions of bearings. Assoc. Prof.: Kiril M. Alexiev, Petia D. Koprinkova-Hristova; Dr.: Vladislav V. Ivanov, Volodymyr V. Kudriashov , Iurii D. Chyrka. AComIn Technology Transfer Workshop on Advanced Techniques in NonDestructive Testing

alongi
Download Presentation

Non contact acquisition of sonic emissions of bearings

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Non contact acquisition of sonic emissions of bearings Assoc. Prof.: Kiril M. Alexiev, Petia D. Koprinkova-Hristova; Dr.: Vladislav V. Ivanov, Volodymyr V. Kudriashov, Iurii D. Chyrka AComIn Technology Transfer Workshop on Advanced Techniques in NonDestructive Testing Sozopol, June 18-19, 2015

  2. Outline • The Acoustic Camera overview and resolution enhancement • Experiment description • Comparison of spectra estimates from single microphone and from the focalized Acoustic Camera • Obtained spectra estimates for different bearings

  3. Acoustic Camera Applications: Acoustic Imagingand Signal Analysis Pictures from WWW

  4. The Acoustic Camera • PULSE LabShop Customized Solution Version 17.1.2 • Array Acoustics Post-processing ver.: 17.1.2.308 Software list: a) Acoustic Test Consultant - Type 7761; b) Beamforming - Type 8608; c) FFT Analysis - Type 7770; d) Time Data Recorder - Type 7708. Frequency range: from 10Hz to 20kHz Wavelength range: from 34.3m to 17.15mm Manufacturer: Brüel & Kjær (Sound and Vibration Measurement A/S)

  5. Resolution Enhancement Trg. 2 Trg. 1 Criteria: Half power (-3dB) 5

  6. Resolution Enhancement B&K “Array Acoustics Post-processing”  1 response Capon mod.  2 responses Trg. Trg. 1 Trg. 2 dB Before After (Obtained result) Center frequency fc=10 kHz. Frequency bandwidth f≈ 2.3 kHz. fc/f ≈23% Range ~0.8 m. Spacing between centers of the speakers ~0.1 m

  7. Beamforming based-on modified Capon algorithm “Delay and Sum” Beamforming Capon mod. Trg. Trg. 1 Trg. 2 dB dB Before After (Obtained result) Center frequency fc=5 kHz. Frequency bandwidth f =0.5 kHz. fc/f =10% Range ~0.75 m; Spacing ~0.14 m 7

  8. Photo

  9. Spectra Estimates SKF old Opened

  10. Bearing Fundamental Frequencies SKF old Opened

  11. The first bearing band SKF old Opened Bad sample emission is more powerful Good sample emission is more powerful Acquisition time, T = 0.25, [s] Frequency resolution, f = 4, [Hz] Quantity of autospectra averages = 100

  12. Spectra estimates Acquisition time, T = 0.25, [s] Frequency resolution 1, f1 = 4, [Hz] No averaging Acquisition time is T Frequency resolution 2, f2 = 256, [Hz] Quantity of autospectra averages = 64

  13. Non-stationary signals The considered spectra difference is at higher frequency range. Thus, such peaks were not removed, yet.

  14. Spatial Filtering

  15. Enhancement of Spectra Difference The difference is not getting worse due to application of the microphone array Beamwidth ~60o Beamwidth >~120o

  16. The Generated Acoustic Map 1 Lower Signal-to-noise ratio - 55 dB Center frequency, fС=10, [kHz] Bandwidth f = 1, [kHz]

  17. The Generated Acoustic Map 2 Higher Signal-to-noise ratio - 55 dB up grow, PSF Center frequency, fС=10, [kHz] Bandwidth f = 1, [kHz]

  18. Spectra Estimates SKF old Opened Hereinafter: Acquisition time, T = 0.25, [s] Frequency resolution, f = 4, [Hz] Quantity of autospectra averages = 100

  19. Spectra Estimates SKF old Opened The difference is much lower than in previous Measurements Session due to greasing

  20. Spectra Estimates SKF old Opened At the room, the background varies at low freq.

  21. Spectra Estimates 2. WBF Good About 20 dB difference Two “same” spectra

  22. Spectra Estimates 3. NSK

  23. Spectra Estimates 4. KBS

  24. Spectra Estimates 5. HF

  25. Spectra Estimates 6. CNR

  26. Spectra Estimates 7. VMF

  27. Spectra Estimates 8. SKF

  28. Spectra Estimates 8. SKF

  29. Main goal is to find collaboration with industry/business. Project AComIn "Advanced Computing for Innovation“ FP7 Capacity Programme. Host – Institute of Information and Communication Technologies at the Bulgarian Academy of Sciences.

  30. Acoustic Camera Applications

  31. Conclusions • Frequency resolution of the Acoustic Camera is modified from 1/3 octave to 4 Hz. • Comparison of the spectra shows opportunity to detect difference to good bearings. • Non-contact diagnosis is implemented. Future Plan: Automatic detection of defects (using the spectra) will be implemented for priori unknown background noise.

More Related