Tuning of IMC based PID controller for stable and integrating time delayed processes.

The internal model control (IMC) and proportion-integral-derivative (PID) controller is proposed for time delay process with stable and integrating process type model. In IMC PID controller the process model of unstable pole part must be cancelled to the zeros of first order filter for better performance of the controller. In this paper we are introduce the first order Pade approximation to simplify the transportation delay term present in model. Pole–zero cancellation and stability of the process have been done by first order low pass filter, which is considered for stable and integrating system with time delay for better performance. The tuning parameters of the PID controller are calculated by the time constant and time delay of the process model. Simulation of the system gives the better comparisons as the previous proposed method. In this method we comparing the three type of integrating error like integral absolute error(IAE), Integral time weighted absolute error (ITAE) and integral square error (ISE) and observe that the suggest method have been given better result as previous method. The tuning of the process of PID controller has improved by first order Pade approximation.