how to analyse a length-force-signal

[liethmac]

Hi there

I have a problem with a signal analysis an I hope you can help me.

As you see in the first picture I have a force (y) and a length (x) axis.

The sensor is moving from left to right and is measuring the force with 200000 samples/s.

Moving speed is 10mm/s. So there is a resolution of 20000 samples/mm.

After that the data ist by a Butterworth-Lowpass-Filter, 2nd order with a cut frequency of 10kHz processed.

my problem: how to find the two points (2nd picture, pink circles) to get the length difference between them

my idea : calculate the red straight lines and then calculate the point of intersection between the lines.

my question : how can I calculate the points of intersection with the Measurement Studio-Support,

which functions do I need, what do I have to keep in mind ?

Thank you

[DianaS]

Hi

maybe you can take the derivative of your signal.

There is a function for that in Measurement Studio Professional and Enterprise edition 'Derivative x(t)'

Than you can see were the edges are (highest or lowest value)

The function is in NationalInstruments.Analysis.Dsp >> SignalProcessing..::.Differentiate Method