Figure 4. Block diagram of PID controller PID-ZN and PID-MZN controller
IV. ZIEGLER-NICHOLS METHOD
A.Empirical method This method is applied to plants with step responses of the form displayed in Fig. 5. This type of response is typical of a first order system with transportation delay. The response is characterized by two parameters, L the delay time and T the time constant. These are found by drawing a tangent to the step response at