An Intuitive Six-DOF Admittance Control Method for Human-Robot Collaboration

Admittance control is a well-established frame-work for enhancing human-robot collaboration. Although it is widely applied in translational tasks, the a six-degree-of-freedom (6-DOF) admittance control involving the use of a handle in both translational and rotational spaces is rarely addressed in the literature. This paper introduces 6-DOF admittance control method that utilizes a handle equipped with a force/torque sensor mounted on the robotic arm to intuitively farme the operation of the end effector. By transforming the force/torque applied to the handle into the operation of the end-effector while preserving the operator's intent, intuitive 6-DOF admittance control is achieved. To eliminate the operational risks associated with the uncertainty of the hand's contact point on the handle, uncertainty shielding is implemented, ensuring stable force/torque calculations. The effectiveness of the proposed 6-DOF admittance control method is validated through an assembly operation and a specific trajectory operation.