Passivity of a class of sampled-data systems: application to haptic interfaces

Passivity of systems comprising a continuous time plant and discrete time controller is considered. This topic is motivated by stability considerations arising in the control of robots and force-reflecting human interfaces ("haptic interfaces"). A necessary and sufficient condition for the passivity of a class of sampled-data systems is derived. An example-implementation of a "virtual wall" via a one degree-of-freedom haptic interface-is presented.