time integral problem

[Tutenhamon]

Hello,

I wanted to move my project from Matlab to Labview but I have some problems. I can received similar result just for dt=100ms. If I change it I cannot after received stabilization. What I want to do: I have a piston pump, which based on a linear motor and I would like to set new values of motion based on flow. More precisely I have desire flow and I compare with flow which I obtained and after I set motion of linear motor. Those described all modules in Labview.( in attachment a picture). Each modules are based on point-by-point integral where I have to set time integration dt. If I put different than 0.1s (100ms) I cannot achieve stabilization. Maybe somebody works with point-by-point integral and knows something about disadvantages that method? Thanks for any help.

PS. To see properly the picture you need acrobat reader and you have to do big zoom.

 

[J.R.]

Hi Tutenhamon,

Do you see this comportement with every other values or with higher/lower values?

You could also test with a normal while loop and not a timed while loop.

regards,

[Tutenhamon]

Hello,

Thank you for replied. I see it with any values. I tried to changed it for any diffrent ways but I cannot achive stability above or below 100mS response time. What is for me strange. In Simulink it works fine but I have all drivers in Labview. I check it with normal while loop too. The same results.

[J.R.]

Tutenhamon,

Is it possible to send your VI so we can have a look at it? It will be easier to examine your code with the VI in front of our eyes.

Regards,

[Tutenhamon]

Of course, with the pleasure 🙂

[J.R.]

Tutenhamon,

Do you know that you can include m-files directly inside LabVIEW? From 8.2, you can do it ! I give you two links to our website :

1) Inside LabVIEW MathScript

2) Working with .m file Scripts in NI LabVIEW for Text-Based Signal Processing, Analysis, and Math

I think it can help you because I can't see what you do wrong because I can't compare your LabVIEW code to MatLab code and more, I don't experience with MatLab. Sorry.

Best Regards,

[Tutenhamon]

Thank you but I don't think if I can use it. I used the Simulink before, it isn't MathScript. I will try to find another way to control it.

Thank you anyway.