Positive realizations with reduced numbers of delays for 2D continuous-discrete linear systems

A new method is proposed for determination of positive realizations with reduced numbers of delays of linear 2D continuousdiscrete systems. Sufficient conditions for the existence of the positive realizations of a given proper transfer function are established. It is shown that there exists a positive realization with reduced numbers of delays if there exists a positive realization without delays but with a greater dimension. The proposed method is demonstrated on a numerical example.