Optimal RIMC-based DLC strategy for time-delayed higher-order integrating and unstable processes with a case study on inverted pendulum

This study explores a double loop control (DLC) mechanism enhanced by a relocated internal model control (RIMC) approach, tailored for complex industrial processes characterized by integrating or unstable dynamics and inherent dead-time. The inner loop stabilization is managed through a proportional-derivative (PD) controller, which is designed adhering to the Routh stability criteria. For the outer loop, the RIMC concept is employed to construct a servo controller. Optimizing the controller settings is achieved using the equilibrium optimizer, a metaheuristic technique. This paper presents an evaluation of the stability and robustness of the newly developed RIMC-enhanced DLC system. Compared to existing methods, this approach demonstrates a significant enhancement in performance metrics. The effectiveness of this strategy is further illustrated through a case study involving an inverted pendulum, where the system efficiently managed disturbance pulses.