Analytical Design of IMC-Based PID Controller for Non-minimum Phase Process with Time Delay

In this article, an internal model control (IMC) scheme-based proportional integral derivative (PID) controller is designed for controlling second order non-minimum phase system with time delay. The design uses IMC filters of higher order for realizing the controller. The novelty of work lies in the design controller based on maximum sensitivity. The proposed design also uses higher order Pade’s approximation for time delay. The closed loop performance is observed with nominal model, perturbed model and for noise in the measurement. The performance is computed using integral square error (ISE) and Integral absolute error (IAE). The controller effort is estimated using a measure called total variation (TV). Further, stability analysis is accomplished for variation in the model parameters and fragility analysis is carried out for uncertainties in the controller.