Alternate checking criteria for reachable controllability of rectangular descriptor systems

summary:Contrary to state space systems, there are different notions of controllability for linear time invariant descriptor systems due to the non smooth inputs and inconsistent initial conditions. A comprehensive study of different notions of controllability for linear descriptor systems is performed. Also, it is proved that reachable controllability for general linear time invariant descriptor system is equivalent to the controllability of some matrix pair under an assumption milder than impulse controllability. The whole theory has been developed by coining two new decompositions for system matrices. Examples are given to illustrate the presented theory