Title: Tuning of multivariable PI/PID controllers for TITO processes using dominant pole placement approach

Authors: Harsha R. Mokadam; Balasaheb M. Patre; Dilip K. Maghade

Addresses: Department of Instrumentation Engineering, Shri Guru Gobind Singhji Institute of Engineering and Technology, Vishnupuri, Nanded-431602, India ' Department of Instrumentation Engineering, Shri Guru Gobind Singhji Institute of Engineering and Technology, Vishnupuri, Nanded-431602, India ' Department of Instrumentation and Control Engineering, Vishwakarma Institute of Technology, Pune-411037, India

Abstract: In this paper, a multivariable PI/PID controller design method based on dominant pole placement approach for two-input-two-output (TITO) interactive processes is proposed. First the TITO process is decoupled into two higher order decoupled processes through a decoupler matrix. Next, a first order plus dead time (FOPDT) model is determined for each higher order decoupled processes. Then, diagonal PID controller is obtained for given performance specifications using the guaranteed pole placement method. The off-diagonal controller of multivariable controller is obtained by simply multiplying diagonal controller with decoupler elements. This higher order off-diagonal controller is reduced in PI form by using Maclaurin series. The performance of the proposed design method is verified on the original interactive system to show its effectiveness for the general class of the TITO systems. Two simulation examples for TITO processes are incorporated to validate the usefulness of the presented algorithm. It can be observed that the high closed-loop performance is obtained using proposed design method and it is comparable with the recent method available in the literature.

Keywords: decentralised control; multivariable control; dominant pole placement; Maclaurin series; decoupler; FOPDT model; TITO process; MIMO process; PI/PID controllers; controller design.

DOI: 10.1504/IJAAC.2013.055094

International Journal of Automation and Control, 2013 Vol.7 No.1/2, pp.21 - 41

Received: 28 Sep 2012
Accepted: 02 Apr 2013

Published online: 12 Jul 2014 *

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