Design of relay and variable structure observers for multi-input multi-output systems with time-lag

The paper deals with design principles of relay and variable structure observers for multi-input multi-output systems with time-lag. We thus have suggested design methods and synthesis of state observers for multi-input multi-output (MIMO) systems with time lag. In the case of the relay observer, high amplification factor is used for the model of the observer. In both cases, namely, relay observer and variable-structure observer, the sliding modes are imposed on the system deliberately. Most importantly, for both the state observers considered the error equation of motion is proved to be globally asymptotically stable.