Open AccessDecentralised PI controller design based on dynamic interaction decoupling in the closed-loop behaviour of a flotation process
Author(s) -
Nomzamo Tshemese-Mvandaba,
Raynitchka Tzoneva,
Mkhululi Elvis Siyanda Mnguni
Publication year - 2021
Publication title -
international journal of power electronics and drive systems/international journal of electrical and computer engineering
Language(s) - English
Resource type - Journals
eISSN - 2722-2578
pISSN - 2722-256X
DOI - 10.11591/ijece.v11i6.pp4865-4880
Subject(s) - decoupling (probability) , control theory (sociology) , settling time , multivariable calculus , pid controller , matlab , closed loop , computer science , variable (mathematics) , process (computing) , control system , control engineering , step response , control (management) , mathematics , engineering , temperature control , mathematical analysis , electrical engineering , artificial intelligence , operating system
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closed-loop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.