Nonlinear Dyn (2012) 67:2847–2856
DOI 10.1007/s11071-011-0193-1
ORIGINAL PAPER
On the global stabilization of Takagi–Sugeno fuzzy cascaded
systems
N. Hadj Taieb · M.A. Hammami · F. Delmotte ·
M. Ksontini
Received: 7 January 2011 / Accepted: 3 August 2011 / Published online: 15 September 2011
© Springer Science+Business Media B.V. 2011
Abstract This paper deals with the problem of the
global stabilization for a class of cascade nonlinear
control systems. It is well known that, in general,
the global asymptotic stability of the cascaded sub-
systems does not imply the global asymptotic stabil-
ity of the composite closed-loop system. In this pa-
per, we give additional sufficient conditions for the
global stabilization of a cascade nonlinear system. In
particular, we consider a class of Takagi–Sugeno (TS)
fuzzy cascaded systems. Using the so-called parallel
distributed compensation (PDC) controller, we prove
that this class of systems can be globally asymptoti-
cally stable. An illustrative example is given to show
the applicability of the main result.
Keywords Fuzzy systems · PDC controller ·
Cascaded systems · Lyapunov stability
N.H. Taieb · M.A. Hammami ( )
Faculty of Sciences of Sfax, Department of Mathematics,
University of Sfax, Sfax, Tunisia
e-mail: MohamedAli.Hammami@fss.rnu.tn
N.H. Taieb
e-mail: nizar.hadjtaieb@yahoo.fr
F. Delmotte
University of Artois, Arras, France
e-mail: francois.delmotte@univ-artois.fr
M. Ksontini
Sfax Preparatory Institute for Engineering Studies, Sfax,
Tunisia
e-mail: mohamedksantini@yahoo.fr
1 Introduction
This work studies the problem of the global stabiliza-
tion of nonlinear cascaded systems of the form
˙ x
1
= f (x
1
,x
2
)
˙ x
2
= g(x
1
,x
2
, u)
(1.1)
where x
1
∈ R
n
,x
2
∈ R
q
and u ∈ R
m
. The functions
f and g are supposed C
∞
and to satisfy f(0, 0) = 0,
g(0, 0, 0) = 0.
Let
˙ x
1
= f (x
1
,x
2
). (1.2)
It is well known that if the differential equation
˙ x
1
= f (x
1
, 0) (1.3)
has x
1
= 0 as an equilibrium point globally asymptot-
ically stable, if the system
˙ x
2
= g(x
1
,x
2
, u) (1.4)
is globally asymptotically stabilized at the origin, uni-
formly on x
1
by a feedback law u(x
1
,x
2
), and if all
the orbits of the closed-loop system
˙ x
1
= f (x
1
,x
2
)
˙ x
2
= g(x
1
,x
2
, u(x
1
,x
2
))
are bounded, then (x
1
,x
2
) = (0, 0) is an equilibrium
point globally asymptotically stable for (1.1)[13, 15].