Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

A mid-ranging control strategy for non-stationary processes and its application to dissolved oxygen control in a bioprocess

Johnsson, Ola LU ; Sahlin, D. ; Linde, J. ; Lidén, Gunnar LU and Hägglund, Tore LU (2015) In Control Engineering Practice 42. p.89-94
Abstract
In this study a modified mid-ranging strategy is proposed where the controller for the secondary manipulated variable uses its own output as its setpoint, possibly with an offset and/or re-scaling. This modification allows the manipulated variables to increase in unison so that the mid-ranging advantage of utilizing the fast dynamics of the primary controller to regulate the process can be achieved also in non-stationary processes, while not adding complexity to the controller. The proposed control strategy has been implemented in pilot-scale (5001) industrial bioprocesses where it is used to control the dissolved oxygen level by manipulating agitator speed and aeration rate. The controller is demonstrated to perform well in these,... (More)
In this study a modified mid-ranging strategy is proposed where the controller for the secondary manipulated variable uses its own output as its setpoint, possibly with an offset and/or re-scaling. This modification allows the manipulated variables to increase in unison so that the mid-ranging advantage of utilizing the fast dynamics of the primary controller to regulate the process can be achieved also in non-stationary processes, while not adding complexity to the controller. The proposed control strategy has been implemented in pilot-scale (5001) industrial bioprocesses where it is used to control the dissolved oxygen level by manipulating agitator speed and aeration rate. The controller is demonstrated to perform well in these, outperforming a reference controller which has previously been shown to give satisfactory control performance. It is also shown in similar experiments that the strategy can easily be adapted to control dissolved oxygen in bioprocesses where the feed rate is controlled using an extremum-seeking controller. The proposed strategy is generally applicable to non-stationary processes where a mid-ranging approach is suitable. (C) 2015 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Mid-ranging control, Process control, Control architecture, Industrial, bioprocess, Dissolved oxygen control
in
Control Engineering Practice
volume
42
pages
89 - 94
publisher
Elsevier
external identifiers
  • wos:000358806700008
  • scopus:84935001422
ISSN
0967-0661
DOI
10.1016/j.conengprac.2015.03.003
language
English
LU publication?
yes
id
58f43404-7b40-4381-9826-af9b0a465836 (old id 7975776)
date added to LUP
2016-04-01 10:42:37
date last changed
2023-11-24 16:13:25
@article{58f43404-7b40-4381-9826-af9b0a465836,
  abstract     = {{In this study a modified mid-ranging strategy is proposed where the controller for the secondary manipulated variable uses its own output as its setpoint, possibly with an offset and/or re-scaling. This modification allows the manipulated variables to increase in unison so that the mid-ranging advantage of utilizing the fast dynamics of the primary controller to regulate the process can be achieved also in non-stationary processes, while not adding complexity to the controller. The proposed control strategy has been implemented in pilot-scale (5001) industrial bioprocesses where it is used to control the dissolved oxygen level by manipulating agitator speed and aeration rate. The controller is demonstrated to perform well in these, outperforming a reference controller which has previously been shown to give satisfactory control performance. It is also shown in similar experiments that the strategy can easily be adapted to control dissolved oxygen in bioprocesses where the feed rate is controlled using an extremum-seeking controller. The proposed strategy is generally applicable to non-stationary processes where a mid-ranging approach is suitable. (C) 2015 Elsevier Ltd. All rights reserved.}},
  author       = {{Johnsson, Ola and Sahlin, D. and Linde, J. and Lidén, Gunnar and Hägglund, Tore}},
  issn         = {{0967-0661}},
  keywords     = {{Mid-ranging control; Process control; Control architecture; Industrial; bioprocess; Dissolved oxygen control}},
  language     = {{eng}},
  pages        = {{89--94}},
  publisher    = {{Elsevier}},
  series       = {{Control Engineering Practice}},
  title        = {{A mid-ranging control strategy for non-stationary processes and its application to dissolved oxygen control in a bioprocess}},
  url          = {{http://dx.doi.org/10.1016/j.conengprac.2015.03.003}},
  doi          = {{10.1016/j.conengprac.2015.03.003}},
  volume       = {{42}},
  year         = {{2015}},
}