PID anti windup

[Remie]

I have built a PID controller in labview. Ive been using time domain math, integral and continous calculation. And it works well. But I need a anti wind up.

Is there a easy way to build this? I want to build it my self, and not use the PID block. Or if anyone could help me using one of the PID blocks, and to get the value from 

Ygain, Yintegration, Yderivation and Y total. This so I can see how the process react on different changes.

If anyone could make an easy example for me it would be great.

I have tried with case loops etc but I dont get it to work properly.

[nitad54448]

Hi

I am using the PID Toolkit so it's easier. What do you need is to reset the error (cancel the I value) when approaching the setpoint value

N

[Remie]

I know about that, but I want to see that value of integration, derivation and gain as a value.

[nitad54448]

HI

I maybe don't understand your question. The Gain, I and D values are depending on the system in place,... you need to tune the values.

N

[Remie]

Hi, I know that, but I want to see in a graph how much each of the do on the outsignal.

[Remie]

Maby it's easier to show when I upload a screenshot. Here there is a line for Ygain, Yintegration, Yderivation and Ytotal. But I havent got anti wind up to work on this. And on the done PID block I cant get this graph. Can anyone help me?

[DavidMaidman]

I am not sure your question is clear. There are lots of ways of dealing with integrator windup, including integrator reset (as mentioned) or by limiting the values that the integrator can output to an acceptable range.

It might help if you can attach you code with comments arround your problem.

Also, there are lots of pre-written VIs and toolkits available to do this. Why do you want to create the VI yourself? Are you trying to do some thing specific?

[Remie]

The reason that I wanted to build the vi myself, is the screenshot I showed over. Where I can see more parameters then in pre-written VIs and tool kits I have tried.

Im going at school, so im going to use it as a academic tool. So I can see how much the gain, integration and derivation do. And this I havent found in any of the pre-written VIs.

I just need the value of Ygain, Yintegration, Yderivation and Ytotal. Y=output.

[Remie]

anyone?

[Ben]

Open the Front panel of teh VI from the PID Toolkit and do a "Save as" and in the dialogs, tell LV to not update the callers.

When you are done saving you will have your own copy of the PID VI that you can play with.

Dig into that VI and find the values you want and create indicators on the icon connector to return those values each time the hacked_PID is called.

Byt the time you get that done and play with it a bit, you will have good idea of how it works while at the same time getting a healthy does "so where does this wire go?".

Ben