topic Normalize plots in LabVIEW

Normalize plots

jhealey — Fri, 08 Jul 2016 12:27:34 GMT

Hi all,

I am trying to normalize plots. I have an accelerometer giving me three axis of data and a proximity sensor giving me data for the rpms of a motor. I am currently using a measurement computing DAQ which runs the NI ULx driver. My overall goal is to be able to see the vibrations as a function of rotational speed.

Thanks

Re: Normalize plots

Gregory — Mon, 11 Jul 2016 21:45:18 GMT

If you could save for LV 2012 or earlier I can take a look. It seems like a very large file size for a single VI. Can you not just divide by the maximum value of the curve to normalize it?

Re: Normalize plots

TommyDunkz — Tue, 12 Jul 2016 22:17:38 GMT

Hi jhealey,

Could you elaborate on what you mean by normalizing the data in this context? Do you intend for each plot to have the same x- and/or y-axis limits? Are you expecting your data to always fall within a certain range?

Re: Normalize plots

Henrik_Volkers — Wed, 13 Jul 2016 09:29:19 GMT

What you look for are order analyses, and you want to resample the data to even angle instead of even time. Have a look at the sound and vibration modules, it all there 🙂

One pulse per revolution is not that much... but it depends what you are looking for and how your system behaves....

Re: Normalize plots

jhealey — Wed, 13 Jul 2016 11:05:40 GMT

Tom,

I like my plots to each be a rpm versus vibrations data. Basically showing that as your speed increases, so does your vibrations.

Thanks

Re: Normalize plots

TommyDunkz — Thu, 14 Jul 2016 14:30:10 GMT

Hi jhealey,

How are you planning on calculating vibration? I am guessing it is based on the x-, y-, and z-axis coordinates somehow?

Re: Normalize plots

jhealey — Thu, 14 Jul 2016 14:50:31 GMT

Tom,

My accelerometer gives me readings for the X, Y, and Z directions. I have converted the voltage outputs into units with gravity. I bundled the readings from each to show one plot with three readings. Is there any way to really make this an rpm vs vibration plot? Preferably on one plot but if one for each direction is needed, that will work for my application.

Re: Normalize plots

Gregory — Thu, 14 Jul 2016 15:46:27 GMT

You want to plot RPMs on the y-axis and vibration on the x-axis? It sounds like you already have the RPMs array. For the vibration array, you could take the magnitude (sqrt(x^2 + y^2 + z^2)) and plot along the x axis. You can either bundle into a cluster, or use the re/im to complex function, and then wire into an xy graph.