Parallel cascade control of dead time processes via fractional order controllers based on Smith predictor

• Published in: ISA transactions Vol. 98; pp. 186 - 197
• Main Authors: Pashaei, Shabnam, Bagheri, Peyman
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.03.2020
• Subjects: Dead time processes; Fractional order controller; Internal model control; Parallel cascade control; Robustness; Smith predictor; Robustness; Smith predictor; Dead time processes; Internal model control; Parallel cascade control; Fractional order controller
• ISSN: 0019-0578; 1879-2022
• DOI: 10.1016/j.isatra.2019.08.047

In this paper, control of stable, unstable and integrating processes with large time delay in the presence of uncertainty, external disturbances and measurement noise is investigated. For this purpose, fractional order controllers in the parallel cascade scheme based on smith predictor are designed. The applied parallel cascade control strategy consists of a set point tracking controller, a disturbance rejection and a stabilizing controller. Set point tracking and disturbance rejection controllers are fractional order controllers and stabilizing controller is designed based on Routh–Hurwitz stability criterion. Also, the robust stability and the performance of the proposed strategy are studied in some details. The numerical simulation results are used to make comparisons with the other researchers’ works to show superiority of the designed controllers. •Combination of smith predictor and parallel cascade control strategy is proposed.•Fractional order controllers are used.•The strategy can be applied to stable, unstable and integrating processes.•Simulation results demonstrate the effectiveness of the proposed method.