Improving Transparency in Teleoperation by Means of Cutaneous Tactile Force Feedback

A study on the role of cutaneous and kinesthetic force feedback in teleoperation is presented. Cutaneous cues provide less transparency than kinesthetic force, but they do not affect the stability of the teleoperation system. On the other hand, kinesthesia provides a compelling illusion of telepresence but affects the stability of the haptic loop. However, when employing common grounded haptic interfaces, it is not possible to independently control the cutaneous and kinesthetic components of the interaction. For this reason, many control techniques ensure a stable interaction by scaling down both kinesthetic and cutaneous force feedback, even though acting on the cutaneous channel is not necessary. We discuss here the feasibility of a novel approach. It aims at improving the realism of the haptic rendering, while preserving its stability, by modulating cutaneous force to compensate for a lack of kinesthesia. We carried out two teleoperation experiments, evaluating (1) the role of cutaneous stimuli when reducing kinesthesia and (2) the extent to which an overactuation of the cutaneous channel can fully compensate for a lack of kinesthetic force feedback. Results showed that, to some extent, it is possible to compensate for a lack of kinesthesia with the aforementioned technique, without significant performance degradation. Moreover, users showed a high comfort level in using the proposed system.