Necessary and sufficient conditions for input-output finite-time stability of impulsive dynamical systems

In [6] a sufficient condition for the input-output finite-time stability (IO-FTS) of time-dependent impulsive dynamical linear systems has been provided in terms of a feasibility problem involving a coupled difference/differential LMI (D/DLMI). In this paper we show that such condition is also necessary; moreover an alternative necessary and sufficient condition for IO-FTS is proved. The latter condition requires the solution of a coupled difference/differential Lyapunov equation (D/DLE) and is shown to be more efficient, from the computational point of view, than the D/DLMI based condition. In order to prove the main result, we exploit the definition of controllability Gramian extended to impulsive systems. An example illustrates the benefits of the proposed technique.