TY - JOUR
T1 - Digital redesign of H∞ controller via bilinear approximation method for state-delayed systems
AU - Shieh, Leang San
AU - Wang, Wei Min
AU - Tsai, Jason S.H.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1998/1/1
Y1 - 1998/1/1
N2 - Two issues are addressed: digitial modeling of the continuous-time state-delayed system; and digital redesign of the observer-based H∞ controller for the continuous-time state-delayed system. The bilinear approximation method together with the linear interpolation is utilized to find an equivalent discrete-time model of the original continuous-time state-delayed system, so that the states of the obtained discrete-time model closely match those of the original continuous-time statedelayed system. In addition, the same idea is used to establish an equivalent digital controller from the analogue H∞ controller for the continuous-time state-delayed system, so that the states of the digitally controlled sampled-data state-delayed system closely match those of the original analogously controlled continuoustime state-delayed system. A discrete-time observer is constructed from the original continuous-time observer via a modified lifting technique, such that the estimated states of the obtained discrete-time observer match those of the original continuous-time observer at the sampling instants. Using the newly digitally redesigned observer-based controllers, the resulting dynamic states of the overall digitally controlled sampled-data state-delayed systems are able to closely match those of the original observer-based analogously controlled continuous-time state-delayed systems. An illustrative example is given to show the digital modeling and digital redesign results for a state-delayed system.
AB - Two issues are addressed: digitial modeling of the continuous-time state-delayed system; and digital redesign of the observer-based H∞ controller for the continuous-time state-delayed system. The bilinear approximation method together with the linear interpolation is utilized to find an equivalent discrete-time model of the original continuous-time state-delayed system, so that the states of the obtained discrete-time model closely match those of the original continuous-time statedelayed system. In addition, the same idea is used to establish an equivalent digital controller from the analogue H∞ controller for the continuous-time state-delayed system, so that the states of the digitally controlled sampled-data state-delayed system closely match those of the original analogously controlled continuoustime state-delayed system. A discrete-time observer is constructed from the original continuous-time observer via a modified lifting technique, such that the estimated states of the obtained discrete-time observer match those of the original continuous-time observer at the sampling instants. Using the newly digitally redesigned observer-based controllers, the resulting dynamic states of the overall digitally controlled sampled-data state-delayed systems are able to closely match those of the original observer-based analogously controlled continuous-time state-delayed systems. An illustrative example is given to show the digital modeling and digital redesign results for a state-delayed system.
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U2 - 10.1080/002071798222073
DO - 10.1080/002071798222073
M3 - Article
AN - SCOPUS:0032123874
SN - 0020-7179
VL - 70
SP - 665
EP - 683
JO - International Journal of Control
JF - International Journal of Control
IS - 5
ER -