PID values from Matlab don't work in LabVIEW model

[PatriciaVcLopes-1213]

Hi All, 

I'm a beginner in LabVIEW. 

I was given a Simulink model and asked to pass it to LabVIEW, after doing this I tested the system's output and they checked in both models. Now, I need to implement a PID and I am using a genetic algorithm to obtain the optimized PID values with Matlab, however, when I use the obtained values in my LabVIEW model the system doesn't have the same behaviour. 

I know that in Matlab the values are gains (Kp, Ki, Kd) and that I need to convert them to time values (Kc, Ti, Td) in minutes. I am using the following formulas: Kp=Kc, Ti = Kp/Ki, Td =Kd/Kp. I even used the "PID structure conversion VI" to do this conversion and still, the system step response is not the same. Also, I have checked the solvers and the time step, and they are the same in both models. 

Could you please help me with this problem?

Thank you so much for your time.  

[User002]

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@PatriciaVcLopes-1213 wrote:

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when I use the obtained values in my LabVIEW model the system doesn't have the same behaviour. 

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Could you attach what you've tried so far? (Either as a .vi file, or as a .zip file of your project.)

That way the experienced members of this forum can better see what you've tried so far.

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I'm a beginner in LabVIEW. 

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Also, if you haven't seen them yet, make sure to check out the "LabVIEW Training Resources" section on the main page of the forum! They can help LabVIEW programmers avoid many mistakes (as we *all* know too well... 😅).

-joeorbob