Improved delay-dependent stability analysis for linear time-delay
systems: Based on homogeneous polynomial Lyapunov–Krasovskii
functional method
Huasheng Zhang, Jianwei Xia
n
, Guangming Zhuang
School of Mathematics Science, Liaocheng University, Shandong 252000, China
article info
Article history:
Received 9 September 2015
Received in revised form
3 December 2015
Accepted 13 February 2016
Communicated by Rongni Yang
Available online 23 February 2016
Keywords:
Linear time-varying systems
Homogeneous polynomial functional
LMI
Stability
abstract
An improved delay-dependent stability condition for linear system with interval time-varying delay is
provided in this paper. Different from previous methods, a homogeneous polynomial Lyapunov–Kra-
sovskii functional is introduced, based on the new Lyapunov–Krasovskii functional method and
wirtinger-based integral inequality technique, a novel delay-dependent stability criterion for mentioned
system is obtained in terms of linear matrix inequalities, which is less conservative than most recent
results. Numerical examples are also provided to show the advantage of the obtained result.
& 2016 Elsevier B.V. All rights reserved.
1. Introduction
Due to the fact that time delays are usually encountered in
various practical systems such as biology, chemical processes,
mechanical engineering, and networked control systems and long
transmission lines in pneumatic systems, and they are often the
main reason of instability and oscillation for time-delay systems.
There has been an increasing research on stability analysis for
time-delay systems in the past several decades [1 –7]. All the sta-
bility criteria for time-delay systems can be classified into two
categories: delay-independent results and delay-dependent ones.
Since more information of time delay was included, the delay-
dependent results are usually less conservative than the delay-
independent ones, especially when the time delays are small.
Numerous efforts have been focused on achieving delay-
dependent stability conditions with less conservativeness for
delayed systems in the recent literature [7–20]. For example,
system transformation method in [8], Jensen inequality method in
[9], discretized Lyapunov functional method in [10], descriptor
model transformation in [11], parameter-dependent Lyapunov–
Krasovskii functional method in [12], Free-weighting matrix
method in [13–16], integral inequality method in [17], augmented
Lyapunov functional method in [18], convex domain method in
[19,20], interval partition method in [21,22], reciprocally convex
method in [23], and wirtinger-based integral inequality method
[24]. It is worth noting that, there is a same characteristic in the
above literature, that is, the selected Lyapunov–Krasovskii func-
tionals are all quadratic function.
On the other hand, as the general form of quadratic Lyapunov
functional, the homogeneous polynomial Lyapunov functionals
(HPLFs) have been proved that can be used to improve robust sta-
bility results obtained by quadratic Lyapunov functionals in [25,26].
And some attention has been paid on constructing HPLFs to deal
with the problem of robust stability for various uncertain systems in
recent years [27–30]. Therefore, we can see that the HPLFs method
is a powerful tool to enhance robust stability for uncertain systems.
Meanwhile, as far as we know, there is no related research on the
stability analysis for time delay systems with the homogeneous
polynomial Lyapunov–Krasovskii functionals (HPLKFs) method in
current literature. Naturally, we have one interesting question: just
as the HPLFs for uncertain systems, could we choose appropriate
HPLKFs instead of quadratic Lyapunov–Krasovskii functionals to
reduce conservativeness of stability results for time-delay systems?
This greatly motivates our study of this paper.
This paper is focused on the stability analysis for linear systems
with interv al time-varying delay . By constructing a novel homo-
geneou s polynomial Ly apun o v—Kras ov ski i functionals (HPL KFs) and
using wirtinger -based integral inequality technique, an improved
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journal homepage: www.elsevier.com/locate/neucom
Neurocomputing
http://dx.doi.org/10.1016/j.neucom.2016.02.025
0925-2312/& 2016 Elsevier B.V. All rights reserved.
n
Corresponding author.
E-mail addresses: zhsh0510@163.com (H. Zhang), njustxjw@126.com (J. Xia),
zgmtsg@126.com (G. Zhuang).
Neurocomputing 193 (2016) 176–180