Accelerometer 1st try need help TIA

[JB2]

gram an input to read acceleration, velocity and position. The
accelerometer takes 5vdc, at 0 acceleration outputs 2.5v and outputs
_+ 1v/g. I've taking the input through a DAQ then multiplied by 9.8
for scaling to m/s^2. I integrate twice, once for velocity and once
for position. I've adjusted for DC levels from the accelerometer. Do
I have to use a peak detect to get the actual position value? I've
also inserted a shift register so that the last position value is
added to the new position each time the loop runs. I've tried taking
200 samples at 1kHz...it appears to be working, but I can't make sense
os the data.

the accelerometer is attached to a mass, which hangs vertically on a
spring. The z axis is the only output.
I've included the file. Any help is much appreciated.

TIA

[tbob]

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@JB2 wrote:
I've included the file. Any help is much appreciated.

TIA

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I didn't see any file.  Try again.

[BrowningG]

Hello JB2,

Thanks for contacting National Instruments. 

What issues are you having with the data?  You should not have to use a peak detect function to determine the position.  Assuming that the issue is related to the integration of your waveform, there are two possible things to try.  The first is that NI does make a Sound and Vibration Toolkit  that provides the necessary VIs to convert an acceleration measurement to a displacement easily. 

The second option, if you do not have the sound and vibration toolkit, is to try to eliminate any DC offset.  Whenever LabVIEW performs integration, some DC offset is introduced.  It will be necessary to remove this DC offset before both the first and second integrations.  The best way to do this is to filter the data using a High Pass FIR Filter.  See this forum post  for information regarding this. 

Please post back if you have any more questions.