Robust PID Controller Design of Time Delay Processes with/without Zero

The PID control system design has been proposed based on the IMC principle for integrating, first order and second order systems with an integrator, and with/without zero. The proposed method of PID controller design is based on the disturbance rejection, which causes the overshoot in the setpoint response. The two-degree-of-freedom (2DOF) control structure has been suggested to eliminate the overshoot in setpoint response. The simulation results show the superiority of the proposed tuning rule over other existing methods, when the controller is tuned to have the same robustness level by evaluating the peak of the maximum sensitivity(M_s). The multiplicative uncertainty bound has been proposed based on norm-bound uncertainty principle for the selection of closed-loop time constant (lambda).