Position sensor to velocity via math?

[djb_rh]

I've got a linear position sensor attached parallel to a shock absorber. Looks like I'm getting good data on a 12V analog input.

So, I know how to dump my data to a CSV, open in a spreadsheet, and then calculate shock velocity from the position data. The question is whether there is a way through a User Defined Variable to do it in the DL-1 analysis software. I've poked and prodded and tried things, but I can't see any way to do it. Can it be done?

Anyone got any feel for whether or not 100Hz is a reasonable sampling rate for this kind of data anyway?


--Donnie

[DaveTurner]

You can differentiate a variable using a user channel - it's under advanced options. It appears to work on the unfiltered data recorded by the device which may or may not be too noisy for you.

As for bandwidth, 100 Hz is more than adequate - the two major resonant frequencieis you'd be interested in are both below 20 Hz (MoTeC software seems to use 40 Hz acquisition rate to make sure all measurements are covered by the Nyquist frequency)

[jlucas]

Donnie, I'd be interested in a copy of that data. Also can you point us to specifically which sensor you used?

Thanks.