Basic Instrumentation Simulation

[Gotchie]

Hello Guys,

I am kind of new to labVIEW programming, I want to learn about PID control regarding controll process. This is the kind of system I want to create,

- A simulation system that will simulate Level Control, Pressure Control and Flow control of a liquid in a cyliner.

- The incorporation of PID control, the system can be controlled by choosing Academic PID, Parallel PID or Ideal PID control structure.

- During the simulation the system will show the different PID time response such as :

a. Rise Time

b. Setlling time

c. % Overshoot

d. Damping Ratio

e. Oscillation Frequency

f. Gain Margin

g. Phase Margin

-The system must show different gauges that will show 'Real Time' Level, Pressure and Flow of Liquid in a Cylinder and the Process Variable Set Point and Controller Output to a Graphical Indicator.

The system is similar to

Examples >> Toolkits and Modules >> PID and Fuzzy Logic Control >> PID >> Simulation-Cascade and FeedForward Surge Tank Level.vi

Thanks in Advance to all who will help me, All insights will be appreciated and especially for an actual program 

Email me here : gotiongco.jrg@gmail.com 

More Power!

[smercurio_fc]

This sounds like a school project. Is it? What have you tried so far? You said it's similar to that specific example. Did you try using that as a base and going from there?

[Gotchie]

Yes it is, I'm studying it independently and I find it difficult to 'reverse engineer' that example since I don't understand how the 'Plant Simulator' Works. Actually, that example is sufficient for the project, the only thing that is lacking is the incorporation of different PID control structure and the time PID parameters/Time Response. 

As of now I'm trying to study the time response functions, i'm trying to get results without transfer function input and just from the PID controller on the example alone, but I'm still out of luck. Any suggestions? 

Thanks a Lot!

[MissFitt]

Hi Gotchie,

Have you tried using Context Help to see what the Plant Simulator is actually doing? You can also double click it and open it up to see what the code behind the SubVI is. I am also including a link to the PID Theory Explained here that might be able to help you out as well. Hope this helps!

Mychal F

[Gotchie]

Yes, I've tried looking at its Sub VI, it's somewhat complicated. It would be easier to understand it if I'll be able to see how the plant simulator works in a simpler program. If its not too much to ask, can you provide me a sample program that includes a PID controller and a Plant simulator working together?

Thanks 🙂

[MissFitt]

Hi Gotchie,

There really isn't much we can do to simplify this example more. You might be able to take out some of the Feed Forward code, but other than that we can't really simplify it. Here is a picture of what Context Help says about the Plant Simulator SubVI.

I have also included a link to PID Control here that explains a little more about what PID is and how it works. The PID Control Toolkit User Manual located here might be able to help you as well. There won't be much more documentation on the Plant Simulator SubVI since it is specific to this example. Hope this helps!

Mychal F

[Gotchie]

Thanks, I'll try to play with the connections and see if I'll be able to understand them. 

But is it possible to incorporate the PID Parameter (Rise Time, Settling Time, Overshoot, Gain Margin, Phase Margin) on the example that I have uploaded? The Example I've Seen regarding the above mentioned parameters works only if the input to the 'Time Response Function', But on the simulation example that I mentioned, I don't see any TF input to the PID since it comes from the Plant to Simulator. Does the Plant Simulator works on a specific Transfer Function?

I've uploaded the 2 files that I wanted to combine. 

Thanks

[David-A]

Hi Gotchie,

When you say you want to combine the two files you've attached I interpret that to mean you want to place the VI inside of the library.  You can do that by opening the VI, clicking Save As, then selecting the llb file.  This will place the VI within the library.

I'm not sure what you mean by incorporate the PID Parameter on the example.  You can look at the Step Response Data from the CD Step Response.vi as shown in the attached image and calculate things like rise time or overshoot.  The CD Gain and Phase Margin.vi already provides Gain Margin and Phase Margin of the resulting simulation.

David A