Fast input-free observers for LPV discrete-time systems

This paper deals with fast input-free partial state estimation for discrete-time LPV systems through functional observers. The system inputs are assumed to be unknown and then the observers reduce to functions of finite sequences of the output only. The existence of the observer is proved by resorting to both the notion of inverse system and the concept of maximal A-invariant subspaces. A constructive approach to derive the explicit equations of the observer is provided. An example illustrates the efficiency and the computational aspects of the method.