PID problem

[franz2]

I have build an apllication, in which I used a PID control.
How can I build a disturbance in my application, so that the PID control regulate my application an I get my setpoint?

Sorry for my bad english
Franz

[tst]

A PID VI needs to be in a loop. Then, in each iteration of the loop, it outputs the new value of your variable.
You can see an example of this in the example finder. Click Help>>Find Examples.
Then, look at the PID examples in Toolsets and Modules>>PID Control>>PID. More specifically, look at the General PID Simulator. This should help you. If it doesn't, you should post your code here and tell us more about your problem.

[franz2]

I have looked at the PID examples, but nowhere there is an example, where a disturbance is given on the PID.

In the attachment you can see my code, which is without mistakes (I hope so). But now I have to build a disturbance in my application and my PID control shoul regulate this out.

Thanks for your help

[franz2]

can somebody help me, please!

[Jochen]

A very simple way to generate a disturbance is changing the setpoint (Sollwert). If you want to tune your PID controller you could generate a step for the setpoint programmatically (e. g. change the setpoint from 0 to 5 immediately).
You should plot the response of your motor to a chart so you could see and analyze the step response (Sprungantwort).

Additional note:
Depending on the system you want to control you might not be very successful with your approach. You have timed your loop with 10 ms. If this is PID cycle time is appropriate for your system you may be able to get a quite stable system. If your system is more dynamical you will run into problems as you are running your application on a Windows PC which is everything else but a deterministic real-time OS.

Best regards,

Jochen Klier
National Instruments Germany

[franz2]

irgendwie klappt es nicht,

anbei sende ich Ihnen ein Bild meiner Anwendung, vielleicht verstehen Sie es dann besser, was mein Problem ist.