PID control with a simulated controlled system

[Stonei]

Hello!

I'm working on a PID control with a simulated controlled system and i have three big problems in it and i need urgend help.

So here are the problems:

1. If i adjust T=3seconds at all filters (PT1/lowpass attitude) for example, the control device acts oddly (look the jpg attachment). If all

    filters are adjusted  at T=9s however, the control  goes off without a hitch?!?! It is possible, that "T" is calculated for digital IIR-filters

    differently to analog-filters resp. what's with the upper limiting frequency?

2. The time (in seconds) in my Graph only agrees with if i adjust the sample frequency at 1Hz. How can i realize it by using the looping

     iteration to calculate and implement the convenient time for the graph as to that?

3. Corresponding to that the abscissa from the Diadem report should also be marked like the waveform graph...but anyhow i can't  get

     it to work?!

I would be pleased if anybody could point me in the right direction?!

With best regards from Germany...

Stonei

...enclosed my VI's (LV v8.2 / Diadem 10.1) and the jpg

[JoBa]

Hello Stonei,

when I try to open your VIs, I'm missing the Sub-VI SR-FlipFlop.vi.
Could you please post the file?

Furthermore, I think you should take a look at the LabVIEW Control Design and Simulation Toolkit.
It would help you tremendously for the task of designing such a control in LabVIEW.

Regards,
Johannes

NI Germany 651730

[Stonei]

Hello!

Thank you very much for answering the message!

For sure I would like to work with the LabVIEW Control Design and Simulation Toolkit but the point is that I have to finish the program as fast as possible! I fear it would take too much time for me now to become acquainted with the Toolkit..

I would be very pleased if you could help me.

Here is the missing VI (SR-flipflop)....

With best regards....

Stonei

[Stonei]

Hallo noch da?

Gruß Dirk

[JoBa]

Hello Stonei,

please excuse the very late reply.

I left the office shortly after your last post and your question was unfortunately left unanswered.

You can modify the values used in the x-axis of the graph with a property node. To create one, right-click on the terminal of the graph and select Create > Property Node.
Then select x-axis and set values for the parameters.

Regarding the graph in DIAdem, you will have to pass timing information to the DIAdem Report Express VI. Right now, DIAdem only has y-axis data to work with, and therefore is not able to generate a correct graph.

I need some clarification regarding your first question, as I wasn't able to reproduce the behaviour you mentioned. I what order are the controls supposed to be used to generate the response curve?

Thank you,
Johannes