Experimental Studies of a Novel 6-DOF Haptic Device

This paper presents experimental studies for increasing transparencies in haptic interaction. In particular, the experimental results of this paper are concerned with the new design and the prototype of a 6DOF haptic device. This device consists of a passive/active spherical joint and the connecting serial link mechanisms. The gravity compensation is accomplished both mechanically and through feed-forward compensation. The passive spherical joint can mechanically compensate for the gravity loading of the spherical active links and the associated connected serial mechanism to the floating platform. It is shown that through implementation of passivity-based controller, closed-loop stability of the system can be achieved when interacting with increased stiffness of the virtual environment.