Repositioned Internal Model Control Strategy on Time-Delayed Industrial Processes With Inverse Behavior Using Equilibrium Optimizer

This paper investigates a repositioned inner-loop stabilized internal model control technique for demanding inverse response industrial processes and bioreactors with integrating/unstable dynamics. A proportional-derivative controller based on Routh stability principles is used to achieve stabilization. For set-point pursuit, the servo controller is built by applying the relocation internal model control principle to the stabilized plant model. The metaheuristic equilibrium optimizer methodology is used to achieve the optimal controller settings of the proposed method. The recommended technique is investigated for managing inverse response processes such as the steam drum level control system, concentration in enzymatic reactors, and continuously stirred tank reactors. A thorough examination of the proposed scheme’s stability and robust performance is also provided. It provides significant improvement in performance metrics when compared with some of the recently reported strategies. Particularly, for the steam drum system, the suggested strategy yields an improvement of over 47% in the disturbance rejection and more than three times faster servo response when compared with the recently reported integral proportional-derivative double control loop strategy.