ABSTRACT
The observer with the input as a discontinuous function of the mismatch in sliding mode is equivalent to the reduced order observer. Using the sliding mode approach, the design procedure for an observer for a time-varying system may be decoupled into r trivial and independent stabilization subproblems. A design methodology for such systems was developed by S. Drakunov and V. Utkin and Y. W. Kim, G. Rizzoni, and V. I. Utkin. The -stage observer was proposed to consist of a discrete time-varying observer to estimate the states at each sensor switching instant and of a continuous system to estimate the state trajectory between the switching instants. Generally speaking, the observer equations are time varying, and the conventional eigenvalue placement methodology is not applicable. The observer design approach described overcomes this difficulty and guarantees convergence.
