Revisiting the Ziegler-Nichols tuning rules for PI control - Part II, The frequency response method
This paper presents an analysis of the Ziegler-Nichols frequency response method for tuning PI controllers, showing that this method has severe limitations. The limitations can be overcome by a simple modification for processes where the time delay is not too short. By a major modification it is possible to obtain new tuning rules that also cover processes that are lag dominated.