Time-varying two-dimensional state-space structures

The paper considers a two-dimensional state-space structure with periodically time-varying matrices. A new equivalent state-transition matrix for such a system is first developed, and this is used to show how the general response formula can be evaluated. Finally, an equivalent time-invariant block structure is presented, with a simplified graphical method for its determination. This form can not only be used as a new means of implementation, but also to easily evaluate the stability of the overall time-varying system