Identifying measured system comparing with simulated

[laskar01]

Hello, I want to be able to match a simulated model

to a measured one.

I have started with outputting a squarewave to a rc lowpassfilter, and I am measuring the output.

In parallell I want to run the simulated responce, and if possible have the simulated responce in the same graph.

I want also be able to use Labviews built in fitting functions somehow.

Greatful for some help!

P.S. This is not a homework problem, I am not a student, I work as an instructor and I am a beginner with Labview.

[Barp]

Hello

Well, I stated from your code below and modified you initial VI to do the tasks you want. If I had to develop myself this code, I would use DAQmx with VIs instead of using the express VIs because I could have more control over it. But since you started with express VIs, then I left those and tried to see if this could would work.

In attachment if my VI. Unfortunately I do not have a board on my computer (I work in R&D software.. 🙂 and I can't test it right now. Please tell if it works...

Here are some other comments:

1. First, trying to place the code in two separate while loops would make the acquisition more complex. I tried to place all the code on the same while loop, Dataflow should allow you to run both code at the same time

2. The Simulation need a Indexer to convert the waveform datatype into scalars. A collector and Resample convert back to waveform to plot on the same graph

3. I converted DDT into waveform

Please let me know if you have any questions...

[laskar01]

Hi Barp, I couldn't run it.

Attaching the screendump. It seems that you have a newer version of the simulation blocks.

[laskar01 · Accepted solution]

Holy shit! It works!

I replaced the blocks in the simulation block with Labview 2010 vi's

After pushing the stop button I got the measured voltage from the rc-filter and the simulated one in the same graph!

This is big!

Thank you Barp!!!

[Barp]

I am glad you were able to make it work. Actually, I have installed a patch for the Control Design and Simulation (CD&SIM) 2010. I would recommend install afterwards or just install the Service Pack 1 for the whole platform.

Glad I could help!