Ziegler-Nichols methods.pptx

PID controller tuning by using Ziegler-Nichols method.

1. PID Tuning using Ziegler-Nichols Method Subject – Control System Kaustubha H. Shedbalkar 8/16/2023 PID Tuning using Z- N method

2. Ziegler Nicholas Methods - Step Input method/ Open loop method. Critical gain - critical period method/ Close loop method. 8/16/2023 PID Tuning using Z- N method

3. Step Input method/ Open loop method 8/16/2023 PID Tuning using Z- N method

4. Step Input method/ Open loop method 8/16/2023 PID Tuning using Z- N method

5. In this method, we obtain experimentally the response of the plant as shown in fig. This method applies if the response to a step input exhibits an S-Shaped curve. The S-Shaped curve may be characterized by two constants, Delay time (L) & Time constant (T). It is determined by drawing a tangent line at the inflection point of S-Shaped curve & determining the intersection of tangent line with time axis & line K on Y-axis. The Ziegler-Nichols suggested, we set the value of parameter Kp , Ti, Td according to the formula shown in table. 8/16/2023 PID Tuning using Z- N method

6. Step Input method/ Open loop method 8/16/2023 PID Tuning using Z- N method

7. Critical gain - critical period method/ Close loop method 8/16/2023 PID Tuning using Z- N method

8. Critical gain - critical period method/ Close loop method 8/16/2023 PID Tuning using Z- N method

9. 8/16/2023 PID Tuning using Z- N method In this method, suppose PID controller is used in the system then Ti is set to infinity & Td is set to zero. Using proportional control action only, increase Kp from zero to critical value Kcr at which the output first exhibits sustained oscillations. The critical gain Kcr & corresponding time period Pcr are determined. The Ziegler-Nichols suggested, we set the value of parameter Kp , Ti, Td according to the formula shown in table.

10. Critical gain - critical period method/ Close loop method 8/16/2023 PID Tuning using Z- N method

11. Thank You. 8/16/2023 PID Tuning using Z- N method