Novel twofold control for delayed industrial processes with integrating and inverse response characteristics

Abstract

Non-self- regulating nature of integrating plant causes their regulation a great challenge to researchers. Presence of time delay and positive zero in such processes makes their control more demanding. A novel control technique is developed for such processes to cope with the difficult situations and achieve enhanced performance and robustness. Suggested method is twofold: first the Inner loop controller’s parameters are adjusted to stabilize the process using maximum sensitivity concept and then the outer loop control block is designed by specifying desired setpoint tracking response in the frame of direct synthesis approach involving single tunable parameter. The tunable parameter’s values are obtained so that the robust stability condition is satisfied along with the justification of robust performance constraint in the presence of unstructured uncertainties. The effectiveness of the proposed method is verified on different plants and its advantages over some existing methods are also highlighted. Suggested approach yields improved performance with less control effort and enhanced robustness.