In many practical applications we deal with a wide class of dynamical
systems that are comprised of a family of continuous-time or
discrete-time subsystems and a rule orchestrating the switching between
the subsystems. This class of systems is frequently called switched
system. Switched linear systems provide a framework that bridges the
linear systems and the complex and/or uncertain systems. The mo- vation
for investigating this class of systems is twofold: ?rst, it has an
inherent multi-modal behavior in the sense that several dynamical
subsystems are required to describe their behavior, which might depend
on various environmental factors. Second, the methods of intelligent
control systems are based on the idea of swit- ing between different
controllers. Looked at in this light, switched systems provide an
integral framework to deal with complex system behaviors such as chaos
and multiple limit cycles and gain more insights into powerful tools
such as intelligent control, adaptive control, and robust control.
Switched systems have been inves- gated for a long time in the control
and systems literature and have increasingly attracted more attention
for the past three decades. The number of journal articles, books, and
conference papers have grown exponentially and a number of fundam- tal
concepts and powerful tools have been developed. It has been pointed out
that switched systems have been studied from various viewpoints.
