Fractional filter IMC-PID controller design for an unstable inverted pendulum system

In this article, a fractional filter internal model control (EMC) based proportional integral derivative (PID) controller is designed for controlling the unstable inverted pendulum system. The system is stabilized by using a compensatory function to cancel out the unstable poles and zeros in the model. Now, the controller is designed for the stabilized model producing a PID controller along with fractional filter. The simulations are performed for set point tracking and disturbance rejection with nominal process model and with perturbations. The results show an improvement in the control performance. Further, robustness analysis is done to check the stability of the closed loop system for parameter uncertainties.