Question

Ziegler nichols and cohen coon advantage and disadvantages

Answer 1

The advantage of PID controller is its feasibility and easy to be implemented. The PID gains can be designed based upon the system parameters if they can be achieved or estimated precisely. Moreover, the PID gain can be designed just based on the system tracking error and treats the system to be "blackbox" if the system parameters are unknown. However, PID controller generally has to balance all three-gains impact to the whole system and may compromise the transient response, such as settling time, overshoots, oscillations. If the system parameters can not be precisely estimated or achieved, the designed PID gains may not resist the uncertainties and disturbances, and thus present low robustness. Even though the PID gains can be well-designed, the PID controller still has low robust ability compared with the robust controller when the system encounters to multiple challenges from the operating environment of the system, such as temperature, weather, power surge, and so on.