2 replies to this topic

[rsk]

As suggested there are methods availlble like ziegler nicholas, for tuning of controllers, but for this one requires model of process beforehand.
In case of unavaillability of model how these controllers can be tuned, please suggest the current approach being followed for optimum tuning.
regards

[Zauberberg]

RSK,

To me, it looks like you need some basic information with regard to controller tuning and feedback control items. These can be found in a few textbooks, such are: "Process Control Systems: Application, Design, and Adjustment by G. Shinskey, or "Essentials of Process Control" by W. Luyben. Also, I believe some of the university textbooks elaborate on those topics as well.

Attached is a piece of information from "Instrument Engineers' Handbook".

 Tuning_PID_Controllers.pdf   1.15MB   76 downloads

[siretb]

As a chemical engineer, working on plants, the Ziegler Niechols proves invaluable to me.
It is certainly not the most up to date method, and does not apply to all situations but it's fairly easy to implement, and will put you on the right track. Too often I see PID "tuned" with stupid P, I and D actions and the Ziegler Nichols helps a lot.
Thank you, Zauberberg, for your post that includes a good paper.