Open AccessRobust internal model controller with increased closed‐loop bandwidth for process control systems
Author(s) -
Arya Pushkar Prakash,
Chakrabarty Sohom
Publication year - 2020
Publication title -
iet control theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.059
H-Index - 108
eISSN - 1751-8652
pISSN - 1751-8644
DOI - 10.1049/iet-cta.2019.1182
Subject(s) - control theory (sociology) , internal model , phase margin , settling time , bandwidth (computing) , overshoot (microwave communication) , pid controller , control system , robustness (evolution) , robust control , step response , computer science , engineering , control engineering , temperature control , control (management) , telecommunications , electrical engineering , artificial intelligence , amplifier , computer network , biochemistry , chemistry , operational amplifier , gene
This study proposes a modified internal model control (IMC) structure in which an additional controller is added to the standard IMC structure to improve the closed‐loop system bandwidth. The resulting structure is evaluated to satisfy standard IMC objectives of nominal performance and robust stability. The novelty of the work is to design a fractional order (FO) filter in the IMC structure so that gain margin ( A m ) and phase margin ( ϕ m ) specifications could be independently satisfied for a first‐order plus time delay (FOPTD) process control plant. The proposed modified IMC (m‐IMC) is simulated for three different FOPTD systems to validate and substantiate the theoretical analysis. The proposed m‐IMC is compared with different integer order as well as FO controllers. The transient performance are compared in terms of rise time ( T r ), settling time ( T s ), maximum overshoot (% M p ) and the effectiveness is measured in terms of integral square error. To validate the viability of the proposed control scheme, it is implemented on a laboratory DC servo‐system.