Acoustic Camera 2012.mp4

Hello, my name is Andrea Grosso and today I will talk to you about the Acoustic Camera software. Transient noise is the noise that changes over time like for example, a start up of a machinery a door slam, or a run up of an engine. To be able to map the sound in this condition is necessary to use the multiple probe solution and a multiple channel front end. The alternative is to relate the measurement to some working condition of the machinery. But this requires additional reference channel and complex method for the calculation. The Microflown Acoustic Camera is a direct method to
measure the particle velocity in the near field. As the velocity is a vector, it is well correlated with a surface vibration, and it is not affected by background noise and reflections. For this reason, the camera can be also used in non-anechoic environment. Compare with acoustic holography and beamforming, the Microflown Acosutic Camera has different advantages. First, it is possible to create any kind
of geometry and shapes of the array. It is important to follow with each probe the curved surfaces. The geometry and size of the array does not
condition the frequency range of the Acoustic Camera, which is always 20Hz-20 kHz. As the method is the direct method the spatial resolution does not depend on the geometry of the array, but only on the spacing between the different probes. The dynamic range is over 40 dB, much higher as compare with acoustic holography or beamforming. As the method does not require complex calculation can be also used by non-acoustic expert. The software is divided into recorder and processing. First, all the data are stored in the hard drive, than it is possible to process all the time history
and use an RPM reference sensor for order tracking. In the visualize tab is possible to show colormaps of velocity, pressure and intensity, in a certain frequency band. spectrogram over time for each probe, octave and 1/3 octave. Also is possible to playback the audio of each
probe and create a video in .avi format. The Acoustic Camera has mainly field of applications in
automotive, aerospace, industrial machinery and consumer goods. The option to deploy a scattered array make it possible to use the Acoustic Camera even in
a very complex environment like a car interior. The Panel Noise Contribution use probes in the triangular mounting which decouple the probe from the surface. The Panel Noise Contribution was performed with the windows method using absorbing material to cover the surface inside the car. With this method was not possible to perform measurement under driving condition. With the Acoustic Camera is possible to perform the
Panel Noise Contribution in real driving conditions. Inside the car high velocity at the surface, does not necessary
mean a high pressure perceived to the driver’s ear. This is because the pressure depends on the
relative panel phase and the transfer path. The add-on for the Acoustic Camera called PNCAR (Panel noise contribution analysis reference-related) use the same hardware of the Acoustic Camera to perform airborne transfer path analysis. Combining together the measurement at the surface of
the car interior and all the transfer functions is possible to synthesize the pressure at driver’s ear position. The software can elaborate spectrograms and colormaps to give an overview of the pressure coming from different panel’s areas and achieve a source ranking which allows optimizing
the trimmer panels in the car interior with a minimum impact on cost for development. The Acoustic Camera becomes, in this way, a tool for both sound source localization and airborne transfer path analysis. Depending on the requirements of the development stage of a product it is possible to choose the most suitable method of analysis and maximize the advantages of the particle velocity sensor in the near field. I hope you enjoyed the presentation for further information contact us at our phone or by email.

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