Multirate output feedback sliding mode control design using reduced order functional observer

This paper proposes a technique for computing discrete-time sliding mode control using the concept of functional observer and multirate sampling. The proposed technique has the flexibility of using a lesser order implicit observer than those employed by standard multirate-output feedback based sliding mode controllers. The paper also proves that the complete state observability of a system is not a necessary condition for the existence of a multirate-output feedback based sliding mode controller. The proposed technique has been validated using numerical examples.