Effects of translational and gripping force feedback are decoupled in a 4-degree-of-freedom telemanipulator

Many high-degree-of-freedom haptic devices and teleoperator systems either do not have grippers or do not provide force feedback in the gripper degree of freedom (DOF). The purpose of this work is to determine the effect of gripper force feedback in relation to Cartesian (translational) force feedback on the execution of telemanipulation tasks. We developed a system for adding an additional DOF of grip force feedback on a 3-DOF Phantom haptic device master, as well as 6-DOF force/torque sensing on each "finger" of a coupled gripper on a Phantom haptic device slave. The internal (grip) and external (translational) forces were measured as users performed a soft peg-in-hole task with various DOFs of force feedback: (1) full force feedback, (2) translational force feedback only, (3) grip force feedback only, and (4) no force feedback. Results show that the level of force applied in the translational and gripping DOFs are decoupled for a 3-DOF telemanipulator with added grip force feedback. This is likely due to the decoupled dynamics of internal and external handforces.