Title: Automatic pairing of large scale MIMO plants using normalised RGA

Authors: Alireza Fatehi

Addresses: Advanced Process Automation and Control (APAC) Research Group, Faculty of Electrical and Computer Eng., K.N. Toosi University of Technology, Seyyed-Khandan, P.O. Box: 16315-1355, Tehran, Iran

Abstract: Relative gain array (RGA) is the most important and popular method of finding the best pairing in MIMO plants. However, selection of the pairs based on RGA is an offline algorithm with some ambiguity. In this article, the normalised RGA (NRGA) matrix is introduced through the combination of the RGA matrix and pairing rules. The pairing problem can be interpreted as an assignment problem by using NRGA. Therefore, Hungarian algorithm can be applied to pair inputs and outputs of the process. Up to this stage, integrity has not yet been considered. If the determined optimal pairing does not satisfy integrity conditions based on the Niederlinski index, the procedure continues through the suboptimal pairings. The algorithm is fully systematic. It is applied for control structure selection of the well known Tennessee Eastman process plant.

Keywords: multivariable control; input-output pairing; relative gain array; normalised RGA; Hungarian algorithm; Tennessee Eastman process; MIMO plants; process control.

DOI: 10.1504/IJMIC.2011.042338

International Journal of Modelling, Identification and Control, 2011 Vol.14 No.1/2, pp.37 - 45

Published online: 21 Mar 2015 *

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