Acceleration to displacement

[carot95]

Hello,

I have an accelerometer connected to an amplifier and a DAQ USB-6000.

As I'm more interested in the position of the different axis, I need to convert the acceleration to displacement.

I tried to put an integral to get the speed and then I would have add another integral for the velocity but it doesn't seem to work as it's giving me the same data of the acceleration.

I attach the vi. If you can help me, that'd be great.

Thank you very much.

Carolina

[James_W]

Is there anything wrong with using the Integral x(t) in the integration and differentiation pallete? (instead of the Blue express VI)

(And those dynamic data type wires are horrible - avoid if you can!)

James

[GerdW]

Hi Carolina,

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@carot95 wrote:

I tried to put an integral to get the speed and then I would have add another integral for the velocity but it doesn't seem to work as it's giving me the same data of the acceleration.

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Your DAQAssistent is set to read "1 sample on demand". Afterwards you try to integrate that one sample: which result do you expect from integrating exactly one sample?

I recommend to get rid of your ExpressVIs, too.

Especially that DAQAssistent can be replaced by proper DAQmx functions easily! (As is also shown in all those DAQmx example VIs coming with LabVIEW!)

[James_W]

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@GerdW wrote:

Hi Carolina,

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@carot95 wrote:

I tried to put an integral to get the speed and then I would have add another integral for the velocity but it doesn't seem to work as it's giving me the same data of the acceleration.

---

Your DAQAssistent is set to read "1 sample on demand". Afterwards you try to integrate that one sample: which result do you expect from integrating exactly one sample?

I recommend to get rid of your ExpressVIs, too.

Especially that DAQAssistent can be replaced by proper DAQmx functions easily! (As is also shown in all those DAQmx example VIs coming with LabVIEW!)

---

Doh - I didn't look at that. I don't have any  devices attached to my PC so I replaced with it with a simulated sine wave!

James

[Henrik_Volkers]

Keep in mind, that small offset errors in the acc. amplifier output end in accelerated position output 🙂

usually you apply a highpass before integration ..  if you have access to the sound and vibration vis: there is an integration vi including HP

DC accelerometers for inertial measurements are available but not cheap... and the better ones need a lot of paperwork to get. (Dual use,, )