Integration of acceleration signal

[Dermo]

I am inputting an acceleration signal into labview as part of a Project from an accelerometer. I
require the velocity and displacement signals, however when I integrate the
acceleration using the integral x(t).vi the waveform is offset. Is this
because of the constant of Integration? I require integration regardless of
the phase, that gives me a positive negative velocity and displacement
signal and I see that the svt integration.vi is used , according to your
website to integrate such signals.I dont have this vi unfortunately.
The signal is a sinusoid. Is there any way to modify the Integral x(t).vi to
give me the results I require or any other solution would be very helpful.
Thank you,

[LocalDSP]

SVT is using an FIR filter to perform the integration. The used filter has a low-frequency cut-off (high-pass) to remove the dc component. You can do the same and apply an appropriate high-pass filter after your integration.

Another approach that may be easier for you is to perfom your integration in an analytical way. Since you know that your signal is a sine tone, you can compute the integrated signals once you know the frequency, amplitude and phase of your acceleration signal. To get this information, use for example the Extract Signal Tone Information.vi in your Analyze>>Waveform Measurements palette.

Check also the following posting that includes an example VI at the end.

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=5
0650000000800000068AF0000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0

[Anatoly2]

the link is dead now, i would like to integrate acceleration signal in time domain as well, can anyone post a working link?

[rpursley8]

Because there is a phase shift, there is a constant value that you can just subtract out to get the correct answer and before you integrate to get displacement. The constant will not be there if you try to acquire a whole number of complete cycles of the sine wave or truncate your data down to the last complete cycles.