which vi can return a average value of amplitude (or peak to peak value ) of a sinusoidal signal?

[gyver.ning@gmail.com]

Hello, Friends.

I am searching a vi, that can return a average value of amplitude (or peak to peak value ) of vibration signal (a sinusoidal signal) in a certain period of time, for example ,1S, 0.5S. I have tried the '' Amplitude and Level Measurement.vi'', but it only return a difference between maximum positiv value and minimum peak value. it is, however, not a average value. can you give me some advise? which vi can return a average value of amplitude (or peak to peak value ) of a sinusoidal signal?

thank you  very much.

[crossrulz]

What I ended up doing is using the Cycle Average & RMS.vi (Signal Processing->Waveform Measurement palette) in a FOR loop.  You need to determine how many cycles are in your waveform to know how many cycles to get.  From there, average the resulting means and/or RMS values.

[CindyShark]

Hey Gyver, 

This is the same question you posted to this thread. Please keep one question per one thread. 

As I posted in the other thread, I would use the Waveform Peak Detection VI in the Waveform Monitoring VIs Pallette. It finds the locations and amplitudes of peaks and valleys in Signal In and outputs an array of all the amplitudes of each peak. You can then average that array using the mean VI. Let me know if this helps!

Regards,

Cindy

[gyver.ning@gmail.com]

Hello,crossrulz

i have tried, but it does not work. because the Cycle Average & RMS.vi can only return a cycle average of sine wave. The cycle average of a perfect sine wave is zero, as computed by the following equation. but i want to get a average value of amplitudse of sine wave, so that i can control the amplitude of the vibration. can you give me more advice?

thanks 

ning

[gyver.ning@gmail.com]

Hallo, CindyShark,

Thanks very much for your advice. i habe tried Waveform Peak Detection.VI and then average the mean value with mean.vi(or  mean PtByPt. vi😞  . but i have found some problems.

the  Waveform Peak Detection VI can only return the peaks OR valleys of the signal. but i want to get all the peaks AND valleys  in the acquisition time, sothat i can calculate the mean their value. Furthermore, the output (amplitude) of this vi produce a cluster of 1 element. it can not connect to the input (process variable) of the PID.vi.  The type of this input of the mean.vi (or mean PtByPt. vi ) is double [64 bit real( 15 digit precision)]. 

Have you yet idea to solve this problem?

Thank you very much.

[Henrik_Volkers]

Try

Extract Single Tone Information VI

Owning Palette: Waveform Measurements VIs

Requires: Full Development System

Takes a signal in, finds the single tone with the highest amplitude or searches a specified frequency range, and returns the single tone frequency, amplitude, and phase. The input signal can be real or complex and single-channel or multichannel. Wire data to the time signal in input to determine the polymorphic instance to use or manually select the instance.

with sinus exitation you can get quite far with it 😉