Contact task by space teleoperation using force reflection of communication time delay

This paper proposes a new strategy for space teleoperation under communication time delay, which makes it possible for an operator to know conditions of a remote manipulator through force reflection of the time delay. Using the proposed strategy, an operator feels as if the manipulator is operated through a virtual spring. Basic algorithm is that difference of command and telemetry data due to the time delay is displayed to an operator by force reflection of a hand controller. Also, the force reflection includes a contact force applied to the manipulator. In operation without contact, force reflection becomes to be zero when the manipulator finishes its motion. Under condition of contact, force reflection continues to be applied even if the manipulator stops its motion. Change of force reflection suggests: occurrence of contact; force release of the manipulator; and manipulator moving. The effectiveness of the proposed approach was confirmed by teleoperation experiment, especially focusing on calculation of force reflection and command input.