On mode-dependent H
1
filtering for network-based
discrete-time systems
Lin Li
a,
n
, Fei Li
b
, Zexu Zhang
c,d,
nn
, Jingcheng Xu
e
a
Department of Control Science and Engineering, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology,
Shanghai 200093, China
b
China Automotive Technology & Research Center, Tianjin 300162, China
c
Deep Space Exploration Research Center, School of Astronautics, Harbin Institute of Technology, 150001, China
d
Department of Mechanical Engineering, University of Victoria, PO Box 3055, STN CSC, Victoria, BC, Canada V8W 3P6
e
School of Astronautics, Harbin Institute of Technology, 150001, China
article info
Article history:
Received 11 April 2012
Received in revised form
25 June 2012
Accepted 22 August 2012
Available online 4 September 2012
Keywords:
H
1
Filtering
Discrete-time systems
Markov chain
Transition probability uncertainty
Linear matrix inequalities (LMIs)
abstract
This paper is devoted to the H
1
filtering problem for network-based discrete-time
systems subject to network communication constraints. The objective is to design a
network-based full-order or reduced-order filter, such that the resulting filtering error
system is mean-square stable, while a prescribed H
1
disturbance attenuation levels is
satisfied. A Markov chain is used to describe the network-in duced delays. Then, a mode-
dependent linear filter is considered, whose parameters are scheduled by the network-
induced delays. By converting the partially unknown transition probability m atrix to be
a known convex description, and using the slack matrix approach, a new less
conservative mode-dependent sufficient condition for the existence of the desired filter
is derived to guarantee that the filtering error system is stochastically stable while
satisfying a given H
1
performance. Based on this condition, the filter design method is
proposed, and by solving some convex linear matrix inequalities, the explicit of the
desired filer gain matrices is also given. Finally, a practical example is inclu ded to
illustrate the effectiveness of the proposed method.
& 2012 Elsevier B.V. All rights reserved.
1. Introduction
Since external noises can cause the measured system
states inaccurate, the state estimation through a filter
has been applied [1–7,9]. As one of the most important
problems in control theory, the filtering problem has
attracted great attention [10–19]. Among all the existing
filter design strateg ies, a well- known a pproach i s the
traditional Kalman filtering, which is based on the
assumption that the external disturbances are Gaussian
white noises [20]. However, when the external distur-
bances are not precisely known, Kalman filtering is no
longer valid. In this case, H
1
filtering can be employed to
solve the corresponding problem. The H
1
filtering aims to
develop a suitable filter to minimize the upper bound of
the L
2
gain from the noise to the filtering error. During the
past few decades, H
1
filtering has received considerable
attention. For example, H
1
filtering problems for singular
time-delay systems, stochastic time-delay systems, LPV
systems were investigated in [21–23], respectively. In
[24], by using a switched Lyapunov function, the H
1
filtering and state feedback control for discrete-time
switched singular systems with unknown inputs was
investigated. The authors in [25] considered a class of
nonlinear continuous plant presented by a Takagi–Sugeno
fuzzy model, and designed a non-fragile H
1
filter, and
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journal homepage: www.elsevier.com/locate/sigpr o
Signal Processing
0165-1684/$ - see front matter & 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.sigpro.2012.08.018
n
Corresponding author.
nn
Corresponding author at: School of Astronautics, Harbin Institute of
Technology, 150001, China.
E-mail addresses: lilin0211@163.com (L. Li), feiliz@163.com (F. Li),
zexu0301@gmail.com, zexuzhang@hit.edu.cn (Z. Zhang).
Signal Processing 93 (2013) 634–640