Human-aware natural handshaking using tactile sensors for Vizzy, a social robot

Handshaking is a fundamental part of human physical interaction that is transversal to various cultural backgrounds. It is also a very challenging task in the field of Physical Human-Robot Interaction (pHRI), requiring compliant force control in order to plan for the arm’s motion and a confident but at the same time pleasant grasp of the human user’s hand based on tactile sensing. In this paper we focus on the second challenge and perform a set of physical interaction experiments between twenty human subjects and Vizzy, a social robot whose hands are instrumented with tactile sensors that provide skin-like sensation. From these experiments, we (i) learn the preferred grip closure according to each user group (ii) analyze the tactile feedback provided by the sensors for each closure. In addition to the robot-human interactions, Vizzy executed handshake interactions with inanimate objects in order to (iii) detect if it is handshaking with a human or with an inanimate object. This work adds physical human-robot interaction to the repertory of social skills of Vizzy, fulfilling a demand previously identified by many users of the robot.