Feedback r-passivity of Lagrangian systems for mobile robot teleoperation

One of the key challenges in mobile robot teleoperation is master-slave kinematic dissimilarity: master device (e.g., joystick) has a bounded workspace, while slave mobile robot can/should cover an unbounded workspace. A direct master position/slave-velocity coupling has been frequently used for this, which, yet, in general, violates passivity of the closed loop system, since the master system with position output cannot be passive. In this paper, we propose a new notion of feedback r-passivity of general multi-dimensional Lagrangian systems, which allows us to achieve such master-position/slave-velocity coupling while enforcing passivity. Its applications to tele-driving of dynamic and kinematic WMRs with constant communication delay are also presented.