کنترل فرایند

کنترل فرایند

اسلاید 1: بسم الله الرحمن الرحيم PID ControllersAction, types and tuningRef 1: Smith & Corripio “Principles and practice of automatic process control”, 3rd ed., Wiley, 2006, Chapter 5 & 7.Ref 2: Yu, Autotuning of PID controllers, 2nd ed., Springer, 2006, Chapters 2 &3.Ref 3: Vilanova & Visioli “PID control in the third millennium, Springer, 2012, Chapter 5.Lecturer: M. A. Fanaei Ferdowsi University of Mashhad

اسلاید 2: 1- Action of PID Controllers If the action is not correctly selected, the controller will not control Reverse action (increase/decrease)In feedback control loop, the multiplication of Process gain (Kp), Control valve gain (Kv), Sensor gain (Km) and Controller gain (Kc) must be positive.Reverse action : If Kp Kv Km > 0 → Kc > 0 2

اسلاید 3: 1- Action of PID Controllers Direct action (increase/increase)To determine the action of a controller, the engineer must know:The process characteristicsThe fail-safe action of the control valveDirect action : If Kp Kv Km < 0 → Kc < 0 3

اسلاید 4: 2- Types of PID ControllersClassic PID:Parallel PID (Ideal PID):Series PID:Range :0.01 to 0.2(0.1)4

اسلاید 5: 2- Types of PID Controllers5

اسلاید 6: 3- Tuning of PID ControllersZiegler-Nichols (1942): Recommended for 0.1< D/t <0.5 ( )More than 250 tuning rules are exist for PI and PID ControllersWhat is the suitable tuning rule? It really depends on your process (Type, Order, Parameters, Nonlinearity, Uncertainty, etc)6

اسلاید 7: 3- Tuning of PID ControllersTyreus-Luyben (1992): Recommended for time-constant dominant processes ( D/t <0. 1 )Ciancone-Marlin (1992): Recommended for dead-time dominant processes ( D/t > 2.0 )7