Commutation condition for stability analysis of switched linear descriptor systems

We study the stability analysis problem for switched linear descriptor systems. Assuming that all subsystems are stable and there is no impulse at the switching instants, we establish a new pairwise commutation condition under which the switched system is stable. We also show that when the proposed commutation condition holds, there exists a common quadratic Lyapunov function (CQLF) for the subsystems. These results are natural and important extensions to the existing results for switched systems in the state space representation.