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A difficult deconvolution...

Started by tramoman June 30, 2005
Hello,

I am trying to model the behaviour of a reactor vessel when some
particles inside the container strike the inner wall using FINITE
ELEMENT MODELLING software.

I reproduced several random particles hitting the wall at different
times and position across the surface of the inside wall.

Now I would like to get rid of the TRANSFER FUNCTION of the container
from the random particles data using the deconvolution to extract only
the particle informations.

I apply an inpulse inside the vessel (the middle) and I acquire the
output on the outer surface.

THe PROBLEM: How can I deconvolve the spectra in a right way?
In fact the TRANSFER FUNCTION of the vessel changes according with the
position of the impact.

The tranfer function of the vessel will be completely different when
considering the position A or position B.


        | |
 posB>  | |
        | |
 posA>  | |> output
        | |
        | |






Can somebody help me please?
What kind of DSP tool should I use?
it is really important for me to solve this problem.

Thanks a lot
M

Is the blind deconvolution the techique suitable for me?
Thanks
Manuel

Deconvolution and Transfer Function are terms from signal processing. A
signal is (usually) a time series with equal time spacing between each
sample, which we write as x[n], for n=0,1,2, .... What exactly are your
x[n]?

Regards,
Andor

Andor,
thanks for getting back to me.



x[n]= acoustic signal originated by the particle impact.
y[n]=acoustic signal output (after the vessel wall
h[n]=Transfer function of my vessel.

So, y[n]=h[n]*x[n]
I want to find x knowing y. The problem is that h is not the same
everytime!
It varies with the position of the particle impact (the output position
is always the same in the middle of the external wall).
How can I estimate h?  Thanks
Manuel

tramoman wrote:
> Andor, > thanks for getting back to me. > > > > x[n]= acoustic signal originated by the particle impact. > y[n]=acoustic signal output (after the vessel wall > h[n]=Transfer function of my vessel. > > So, y[n]=h[n]*x[n] > I want to find x knowing y. The problem is that h is not the same > everytime! > It varies with the position of the particle impact (the output position > is always the same in the middle of the external wall). > How can I estimate h? Thanks > Manuel
You obviously can't do it with a single measurement of y[n]. With two or more sensors, you might be able to locate the point of y[n]'s origin and so know something about h[n] there. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������