Optimization of PID Controller Parameters for First Order plus Time Delay Process

Pressure control could be a key process variable in industrial sector because pressure provides an important condition for air-conditioning, chemical reaction, boiling, extrusion, vacuuming, and distillation. Worse pressure control will cause critical quality, productivity and safety issues at the same time excessive pressure within a closed container will result in dangerous explosion. Hence, it is highly important to maintain the pressure at desirable range even in the presence of disturbance and the change in set point. Usually the pressure is controlled by Proportional Integral Derivative (PID) controller in industries because of its higher performance and simple structure over other controllers. The PID controller was designed using Z-N tuning method. Further the PID values were optimized for higher performance by using Pattern Search and Genetic Algorithm. Finally, the response of optimized PID controller was compared with standard Z-N PID controller. The error performance criteria like ISE, IAE, and IATE were used for comparison.