  This paper deals with the analysis of input/output-to-state stability (IOSS)
and construction of state-norm estimators for continuous-time switched
nonlinear systems under restricted switching. Our contributions are twofold.
First, given a family of systems, possibly containing unstable dynamics, a set
of admissible switches between the subsystems and admissible minimum and
maximum dwell times on the subsystems, we identify a class of switching signals
that obeys the given restrictions and preserves IOSS of the resulting switched
system. Second, we design a class of state-norm estimators for switched systems
under our class of stabilizing switching signals. These estimators are switched
systems themselves with two subsystems -- one stable and one unstable. The key
apparatus for our analysis is multiple Lyapunov-like functions. A numerical
example is presented to demonstrate the results.
