Define PID parameters in Simulink

[Destroyer]

Can anyone tell me how I can define my P I and D parameters in Simulink. If I change my parameters of my PID-regulator, my proces value graph changes very much with each change of PID values. I tried to use Ziegler Nichols but it gives very bad results. I need to know a method how I can optimalise my values of my PID.

Thanks a lot

 

[xnuke]

Just out of curiosity, why are you trying to tune a PID loop in Simulink? I've had no problems tuning PIDs using Ziegler-Nichols tuning rules. More help may follow if you describe the reason you trying to do this and your system model structure... xnuke

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