On Controllability and Near-controllability of Multi-input Discrete-time Bilinear Systems in Dimension Two

This paper completely solves the controllability problems of two-dimensional multi-input discrete-time bilinear systems with and without drift. Necessary and sufficient conditions for controllability, which cover the existing results, are obtained by using an algebraic method. Furthermore, for the uncontrollable systems, near-controllability is studied and necessary and sufficient conditions for the systems to be nearly controllable are also presented. Examples are provided to demonstrate the conceptions and results of the paper.