A geometric constraint-based approach to force and motion coupling between real and virtual mechanisms

This paper presents a new stable controller design for use with a general 6-d.o.f. robotic haptic device. A virtual manipulator concept is developed that couples the haptic device kinematics with the constraints of a simulated manipulator. Using impedance-based constraints, the haptic device is controlled to oppose applied forces in directions orthogonal to the motions of the virtual manipulator. The virtual manipulator kinematics constrains the haptic device motion, allowing motion to simulate specific virtual mechanisms. The implementation is illustrated using experimental simulations.