Stabilization and analytical tuning rule of double-loop control scheme for unstable dead-time process

29th Symposium of Malaysian Chemical Engineers 2016

Ugon, B.^1 ; Nandong, J.^2 ; Zang, Z.^3

Department of Foundation in Engineering and Science, Curtin University Malaysia, CDT 250, Sarawak, Miri

98009, Malaysia^1

Deparment of Chemical Engineering, Curtin Univerisity Malaysia, CDT 250, Sarawak, Miri

98009, Malaysia^2

Department of Electrical and Computer Engineering, Curtin University Malaysia, CDT 250, Sarawak, Miri

98009, Malaysia^3

关键词: Dead time process;    Dead-time systems;    Double-loop control;    Performance robustness;    PID controllers;    Stability analysis;    Stability regions;    Tuning method;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/206/1/012060/pdf
DOI  :  10.1088/1757-899X/206/1/012060

来源: IOP

【 摘 要 】

The presence of unstable dead-time systems in process plants often leads to a daunting challenge in the design of standard PID controllers, which are not only intended to provide close-loop stability but also to give good performance-robustness overall. In this paper, we conduct stability analysis on a double-loop control scheme based on the Routh-Hurwitz stability criteria. We propose to use this unstable double-loop control scheme which employs two P/PID controllers to control first-order or second-order unstable dead-time processes typically found in process industries. Based on the Routh-Hurwitz stability necessary and sufficient criteria, we establish several stability regions which enclose within them the P/PID parameter values that guarantee close-loop stability of the double-loop control scheme. A systematic tuning rule is developed for the purpose of obtaining the optimal P/PID parameter values within the established regions. The effectiveness of the proposed tuning rule is demonstrated using several numerical examples and the result are compared with some well-established tuning methods reported in the literature.