N. Linard et al., Identification of a nonlinear plant under nonlinear feedback using left coprime fractional based representations, AUTOMATICA, 35(4), 1999, pp. 655-667
It has been shown that the set of all nonlinear plants stabilised by a know
n linear controller, which also stabilises a linear nominal model of the pl
ant, can be parametrised by a stable operator known as the Youla-Kucera par
ameter. By utilising this description it is possible to convert the closed-
loop plant identification problem to one of open-loop identification. This
paper extends previous work by allowing the model of the nominal plant and
the controller in the above scenario to be nonlinear. The ideas rely on a c
oncept of differential coprimeness for nonlinear fractional system descript
ions. (C) 1999 Elsevier Science Ltd. All rights reserved.