Machinery Maintenance with the Acoustic Camera

Transcription

1 Machinery Maintenance with the Acoustic Camera, Sept VDMA Forum

2 The GFaI e.v. and gfai tech GmbH The GFaI e.v. is a non-profit research association, founded and based 1990 in Berlin / Germany. More than 120 employees work on scientific projects, R&D tasks and services. GFaI is engaged in the promotion and advancement of R&D in applied computer sciences and organizes the industrial joint research. Founded % daughter of GFaI e.v. Development Production global distribution of advanced innovation technologies

3 Expertise / Departments Departments: Image Processing 3D Data Processing Graph Based Engineering Systems Computer Aided Facility Management Signal Processing (Acoustic Camera) Project groups: Adaptive Modeling and Pattern Recognition Document Management Fuzzy Logic Applications Information Systems Multimedia Process Automation Robotics Sensors

4 Content Introduction to the Acoustic Camera and Sound Localization Use of the Acoustic Camera for MRO Conclusions

5 The Acoustic Camera

6 Sound becomes visible

7 Localization principle Basis of the mapping in the space-time domain with NoiseImage is: P( t, r ) = 1 N N i= 1 p( t i ( r )) this formula is long known from Delay-and-Sum Beamforming : Delay-and-sum Beamforming, the oldest and simplest array signal processing algorithm [1] [2]

8 Localization principle source source left sensor right sensor left sensor right sensor runtime delay runtime delay

9 Localization principle Microphone-Array Photo Plane y ' x ' y z x picture point actually calculated different distances r i lead to different runtime delays t i to each microphone

10 Beamforming f ( x, t) D 1 w 1 excitement D 2 D 3 w 2 w 3 + 1/M fˆ ( x, t) f ˆ ( x, t) = 1 M M i= 1 w i f i ( x,( t )) i τ = i r i c p(t) p(t): sound pressuretime-line t 1 t 2 t 3 f i ( x, t) i w 4 D 4 = τ min i ( τ ) i fˆ ( x, t) pˆ effective value of p at place x: eff ( x) pˆ eff ( x, n) = 1 n n 1 k = 0 fˆ 2 ( x, t k ) t 4 t

11 Beamforming

12 MRO with the Acoustic Camera MRO = Maintenance, Repair and Operations: - Prevent material failure and machinery downtime - Needs to be quick, reliable and efficient Sound can be an indicator for irregularities in the machine => The Acoustic Camera helps to find the problem [3]

13 MRO with the Acoustic Camera Spectrogram of one pressing cycle [3]

14 MRO with the Acoustic Camera Spectrogram of a timeframe between two pressing cycles That s where actually the problem occured [3]

15 MRO with the Acoustic Camera Acoustic Picture for the marked areas in the spectrogram Problematic areas get visible No more trial and error Faulty gear could be detected and exchanged directly [3]

16 MRO with the Acoustic Camera Comparison of the spectrograms before and after the repair: before after [3]

17 Conclusions - The Acoustic Camera makes sound visible - Contact-free measurement, which can be performed while the machine is running - Fault can be found fast and easily - Savings in this case: days of machine downtime [3]

18 Thanks for your attention! gfai tech GmbH Volmerstraße Berlin Tel. (030) Fax. (030) Mobil kerscher@gfaitech.de

19 References [1] Array Signal processing Don H. Johnson, Dan E. Dudgeon, 1993 by PTR Prentice-Hall, Inc. [2] Gunnar Heilmann, Magdalena Böck, Dirk Döbler: Exploring the limitations and expectations of sound source localization and visualization techniques; InterNoise 2014 [3] Magdalena Böck, Benjamin Vonrhein, Marc Mehlhaff, Ulrich Meyer: The Acoustic Camera as a tool for machinery maintenance; InterNoise 2015 All other references by GFaI e.v. and gfai tech GmbH