A new observer, namely a cascade observer, for a general class of nonlinear SISO systems was presented by the authors [1]. Inspired by but different from a highgain observer, the cascade observer features a cascade structure and adaptive observer gains. In doing so the cascade observer attempts to overcome some of the typical problems that may pose to a high-gain observer. Based on the cascade ...

There is a basic assumption in using state feedback control, i.e., we assume that all the state variables are available for direct measurements. However, in many situations the complete state is not available; so it is necessary to obtain an estimate of the current state of the given system from measurements of its output. For this purpose, Luenberger (1964, 1966) showed how to construct an obs...