enveloping pulses

[limavolt]

Hi,

I am rookie in labview,

I have signal from the sensor vibration look like

In one group of "pulse" there are some vibration, I have try to make this signal become one "big pulse" so from this graph the result is just two pulses.

is there any possibility using labview?

[mikeporter]

In thory yes, but there are some issues that need to be cleared up -- a really high noise floor, compared to the data. For example, the ringing at the beginning of the sample, is that really there or is that electrical?

Mike...

[limavolt]

Hi Mike,

Yes, I have tried to reduce the noise, I will try to reduce more.

There is a DC offset near, I just tried to add with a number to make it 0.

another posibility is to make this signal digital, so the noise on the floor is gone.

but I do not know how to make several signal in the nearest place become one pulse

[pauldavey]

Once the noise/interference is dealt with, you can have a look at this:

http://en.wikipedia.org/wiki/Analytic_signal

[mikeporter]

You said the signal is vibration data, so the sensor is an accelerometer? Those devices are very noisy under the best of conditions and very susceptable to electrical noise from the environment. It is critical therefore that you get the signal conditioning as close to the sensor as possible.
If you can find a unit where the sensor and conditioning are integrated into a single package, that would be ideal.

Mike...

[limavolt]

Thx for all the sugestions,

I have try with Fast Hilbert Transforms like in http://zone.ni.com/reference/en-XX/help/371361H-01/lvanlsconcepts/hilbert_transform_analytic/

here the part of my VI

but the result is not that I want, the waveform in graph 21 is the same with the graph 17.

or I made mistake with the program?

[P@Anand]

Please attach the data in array (Set the values as default or make a constant) inside LabVIEW. It will be good if you can attach the code in 2011 version.

[pauldavey]

Just try plotting the "r" output of the RE/IM -> R/Theta function.