Asymptotic stability of interconnected passive non-linear systems

This paper addresses the problem of stabilization of a class of internally passive non-linear time-invariant dynamic systems. A class of non-linear ma rginally strictly passive (MSP) systems is defined, which is less restricti ve than input-strictly passive systems. It is shown that the interconnectio n of a non-linear passive system and a non-linear MSP system is globally as ymptotically stable. The result generalizes and weakens the conditions of t he passivity:theorem, which requires one of the systems to be input-strictl y passive. In the case of linear time-invariant systems, it is shown that t he MSP property is equivalent to the marginally. strictly positive real (MS PR) property, which is much simpler to check. Copyright (C) 1999 John Wiley & Sons, Ltd.