High-Fidelity Haptic Device

This demonstration presents our one degree-of-freedom high-fidelity haptic device. Electromagnetic drives are subjected to an inherent inertia-torque tradeoff that fundamentally limits transparency: the higher the torque, the higher the inertia. Based on a dual-stage design, our actuator is not subjected to this tradeoff and is able to approach perfect transparency for human users, combining very low inertia and high dynamic range. It comprises a large, proximal motor and a small, distal motor to reproduce the transients. The two stages are coupled by a viscous clutch based on eddy currents that, without contact, accurately transforms slip velocity into torque. A first demonstration evaluates the participant ability to detect small haptic details and shows that the high-level degree of transparency of the dual-stage drive allows users to detect details that are ten times smaller in magnitude than when using a conventional design. A second demonstration illustrates an application for microteleoperation, where forces to be rendered are highly dynamic.