A. Isidori et al., A note on the problem of semiglobal practical stabilization of uncertain nonlinear systems via dynamic output feedback, SYST CONTR, 39(3), 2000, pp. 165-171
It is known that if a system can be (robustly) globally asymptotically stab
ilized by means of a feedback that is driven by functions that are uniforml
y completely observable (UCO), then this system can be practically semiglob
ally stabilized by means of(possibly dynamic) output feedback. This papers
discusses a significant structural hypothesis under which the existence of
a dynamic feedback driven by UCO functions is guaranteed. The class of syst
ems which satisfy this hypothesis includes any stabilizable and detectable
linear system and any relative degree one nonlinear system which is stabili
zable by dynamic output feedback. In particular, the hypothesis does not re
quire the system to be minimum phase. (C) 2000 Elsevier Science B.V. All ri
ghts reserved.