IMC-PID tuning method based on sensitivity specification for process with time-delay

• Published in: Journal of Central South University of Technology. Science & technology of mining and metallurgy Vol. 18; no. 4; pp. 1153 - 1160
• Main Authors: Zhao, Zhi-cheng, Liu, Zhi-yuan, Zhang, Jing-gang
• Format: Journal Article
• Language: English
• Published: Heidelberg Central South University 01.08.2011
• Subjects: Engineering; Metallic Materials; integrating process; robustness; sensitivity; internal model control-PID; parameters tuning; process with time-delay
• ISSN: 1005-9784; 1993-0666
• DOI: 10.1007/s11771-011-0817-0

To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID (IMC-PID) controller was proposed for the first order plus time-delay (FOPTD) process and the second order plus time-delay (SOPTD) process. By approximating the time-delay term of the process model with the first-order Taylor series, the expressions for IMC-PID controller parameters were derived, and they had only one adjustable parameter λ which was directly related to the dynamic performance and robustness of the system. Moreover, an analytical approach of selecting λ was given based on the maximum sensitivity M s . Then, the robust tuning of the system could be achieved according to the value of M s . In addition, the proposed method could be extended to the integrator plus time-delay (IPTD) process and the first order delay integrating (FODI) process. Simulation studies were carried out on various processes with time-delay, and the results show that the proposed method could provide a better dynamic performance of both the set-point tracking and disturbance rejection and robustness against parameters perturbation.