Haptic teleoperation of a pair of WMRs with mixed physical/virtual constraints

Abstract

A novel framework of haptic teleoperation of a pair of nonholonomic wheeled mobile robots with mixed physical/virtual constraints is presented in this thesis. The proposed framework enables a remote single user to teleoperate the overall motion, while cooperatively squeeze-grasping a common deformable object. Under the mixed constraint, although master interface is free to move, the slave robots have limitation about their motion. To accept/accommodate the mixed constraint, we design haptic feedback and local autonomous control following human command with feasible set, which is defined by all possible motion under mixed constraint on the instant. For mathematical expression, nonholonomic passive decomposition \cite{djlee2010TRO, djlee2008IFAC08} is utilized to decompose the overall motion into the two aspects: grasping shape system and locked overall system. Using theses two aspects, we design semi-autonomous teleoperation architecture where a haptic feedback is designed to inform the human user of feasible command direction, while a local autonomous control drives the pair to follow the human command as much as permissible by the mixed constraint. Real experiment is also performed to support the theory.