A quantitative condition for the well-posedness of interconnected dynamical systems

A sufficient condition for the well-posedness of interconnected dynamical systems is reported. The condition is stated in terms of the uniform instantaneous gains of subsystems and interconnections, and includes Vidyasagar's condition [8] as a special case. The result is useful for testing the validity of the dynamical model of a large-scale system which is obtained by combining the models of subsystems.