How to smooth the signal?

[Dmitri Eskine]

Hi, everybody!

What is the easiest way to get rid of ripples on your signal?

What I mean - I have a signal with occasional outbursts of +- 5 mV and I do
not want to register them. At the same time, I am recording several signals
in time and do not want to violate the sequence. The table of results has to
look like usually, only the points which are out of the normal sequence are
absent or replaced by the previous value.

At the same time, I do not want to process the entire array before
recording, but I want to do this "filtering" or "smoothing" during the
acquisition with presentation of measured data on screen in real time.

Thank you in advance for the help.

Dmitri

[Doug (CapeFl)]

You say the 'easiest way', of which there are many.
One way is to use the 'In Range' VI from the Functions>Comparison palette. It will only pass values within the range use specify.

Another is to put your data capturing vi in a For loop (N = 3, for example). Your output goes to a shift register on the right, with multiple shift registers on the left (say 3) to hold data from previous 3 loops. Wire these 3 shift registers (your last 3 readings) to a 'compound arithmetic add' vi, then divide by 3, you get an average - which in essence filters your data. Every three samples, an averaged output is provided.
Just some ideas, Good Luck, Doug

[Patekkio]

It seems you've got the board resolution (20 V/2^12=4.88 mV).
It would much more correct and accurate if you use a less wide range (e.g. +-5V or less), if it's possible, instead of any kind of filter!

[MSyafiq]

dear all.

I also has problem to smooth the analog signal from devices.

the output get is too much noise

so gow to making it become smooth

used the compactRIO 9073 with NI 9025 analog module

here attched the output measured and also the block diagram putting in powerpoint slide.

any suggestion such must add any filter or pid or something to smooth that signal

thank you

MSyafiq

[GerdW]

Hi MSyafiq,

please attach a PDF or just some pictures (like PNG) instead of a bulky PPT...

Did you notice the age of that thread? Why don't you created your own new fresh thread?

[altenbach]

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@GerdW wrote:

Why don't you created your own new fresh thread?

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Continued here

[MSyafiq]

yes. I noticed that age.

but I also already try to create new thread, but no replied

http://forums.ni.com/t5/LabVIEW/how-to-making-smooth-the-analog-input/m-p/2673287

ok, actually I am trying to get analog input from a torque meter, the input is voltage,

and I am used the NI 9073 compact RIO with the NI 9025 analog module.

I am able to get the signal, but too much noise.

so, how to reduce that noise, just get torque signal,

what should I used,

any filter such band pass filter or what,

any suggestion.

I am still new with the compact RIO and labview, so hope any one expert can help me

thank you

regard

MSyafiq

[altenbach]

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MSyafiq wrote:

but I also already try to create new thread, but no replied

---

Then please keep the discussion in your other thread instead of adding technical information here.

You should also know that we currently have a weekend and the holidays are coming up. Most likely there will be significantly less traffic here in the forum, so you might have to wait a little bit for an answer.

[MSyafiq]

http://forums.ni.com/t5/LabVIEW/how-to-making-smooth-the-analog-input/m-p/2673285

[chrissheffuni]

How quickly do you need to acquire the data? if its not a very dynamic test have you considered oversampling and averaging your data? The NI9205 can acquire at 250ks/S