Design of a Variable Structure Observer for Discrete-Time Systems Considering the Computation Delay.

It is well known that a discrete-time variable structure observer can be designed by reducing the design problem to an output feedback control problem. This approach, however, is valid only for a restricted class of plants. Considering the computation delay, we propose a new method for direct design of a discrete-time variable structure observer. The proposed design method reduces an observer design problem to a state feedback control problem after a coordinate transformation. A numerical example is presented to show that proposed method can be applied to a problem that cannot be designed by reducing to an output feedback control problem.