“A Modified LQG Algorithm (MLQG) for Robust Control of Nonlinear Multivariable Systems”
Authors: Jens G. Balchen,Affiliation: NTNU, Department of Engineering Cybernetics
Reference: 1993, Vol 14, No 3, pp. 175-180.
Keywords: Multivariable control, robustness, tuning
Abstract: The original LQG algorithm is often characterized for its lack of robustness. This is because in the design of the estimator (Kalman filter) the process disturbance is assumed to be white noise. If the estimator is to give good estimates, the Kalman gain is increased which means that the estimator fails to become robust. A solution to this problem is to replace the proportional Kalman gain matrix by a dynamic PI algorithm and the proportional LQ feedback gain matrix by a PI algorithm. A tuning method is developed which facilitates the tuning of a modified LQG control system (MLQG) by only two tuning parameters.
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DOI: 10.4173/mic.1993.3.5DOI forward links to this article:
| [1] Dong T. Nguyen and Asgeir J. Sørensen (2009), doi:10.1016/j.conengprac.2009.03.001 |
| [2] Asgeir J. Sørensen, Svein I. Sagatun and Thor I. Fossen (1996), doi:10.4173/mic.1996.2.6 |
| [3] A.J. Sørensen, S.I. Sagatun and T.I. Fossen (1996), doi:10.1016/0967-0661(96)00013-5 |
| [4] Asgeir J. Sørensen, Svein I. Sagatun and Thor I. Fossen (1995), doi:10.1016/S1474-6670(17)51646-8 |
| [5] B. Javling, J.G. Balchen and S. Strand (1993), doi:10.1016/S1474-6670(17)48432-1 |
| [6] Dongya Zhao, Hao Liang and Sarah K Spurgeon (2018), doi:10.1177/0142331218778108 |
| [7] Jens G. Balchen (1998), doi:10.1007/978-94-011-5094-1_10 |
[1] AMUNDSEN, S. (1992). Modeling and control of rotary kiln processes, MSc Thesis at Dept. of Eng. Cybernetics, The Norwegian Inst. of Technology.in Norwegian.
[2] BALCHEN, J.G., ENDRESEN, T., FJELD, M. OLSEN, T.O. (1973). Multivariable PID estimation and control in systems with biased disturbances, Automatica, 9, 295-307 doi:10.1016/0005-1098(73)90054-X
[3] BALCHEN, J.G. (1984). A quasi-dynamic optimal control strategy for non-linear multivariable processes based upon non-quadratic objective functionals, Modeling, Identification and Control, 5, 195-209 doi:10.4173/mic.1984.4.2
[4] BALCHEN, J.G., (1993). Algorithms for the control of multivariable processes with saturating control variables, Modeling, Identification and Control, 14, no. 4.to appear doi:10.4173/mic.1993.4.3
[5] DI RUSCIO, D. BALCHEN, J.G. (1992). A state space model for the TMP process, Considered for inclusion in the Journal of Pulp and Paper Science.
[6] JALVING, B., BALCHEN, J.G. STRAND, S. (1993). Modified LQG-control and quasi-dynamic optimal control for non-linear multi-variable processes, Paper accepted for IFAC World Congress, Sydney, Australia.
[7] JOSEPH, P.D., TOU, J. (1961). On linear control theory, Trans AIEE.Appl. and Industry, 80, 193-196.
[8] KALMAN, R.E., BUCY, R.S. (1961). New results in linear filtering and prediction theory, Trans. ASME. J. Basic Eng., 83D, 95-108.
[9] LIE, B. (1990). Control structures for polymerization processes applied to polypropene manufacturing, Dr. Ing. thesis, Department of Engineering Cybernetics, The Norwegian Inst. of Technology. Report no.: 1990-82-W.
[10] LIE, B.and BALCHEN, J.G. (1992). A comparison of strategies for the control of a polypropene reactor, Proc. 3rd IFAC Symposium on Dynamics and Control of Chemical Reactors, Distillation Columns and Batch Processes - DYCORD+´92..Pergamon Press, London.
[11] VALDERHAUG, AA., BALCHEN, J.G. (1992). : Modelbased control of the ferrosilicon process, 3rd IFAC Symposium on Dynamics and Control of Chemical Reactors, Distillation Columns and Batch Processes - DYCORD +´92..Pergamon Press, London.
[12] ZIEGLER, J.C., NICHOLS, N.B. (1942). Optimum settings of automatic controllers, ASME Transactions, 64, No. 8, p. 759.
BibTeX:
@article{MIC-1993-3-5,
title={{A Modified LQG Algorithm (MLQG) for Robust Control of Nonlinear Multivariable Systems}},
author={Balchen, Jens G.},
journal={Modeling, Identification and Control},
volume={14},
number={3},
pages={175--180},
year={1993},
doi={10.4173/mic.1993.3.5},
publisher={Norwegian Society of Automatic Control}
};