Direct User-to-user Haptic Interactions via Remote Dynamic Proxies over Wave-domain Communications

This paper investigates the stability of distributed direct user-to-user networked haptic interaction with remote dynamic proxies and passive wave domain communications. Considering fixed communication delays and fixed and low data transmission rate over the network, the paper develops the multirate state space model of the haptic system and uses eigenvalue analysis to determine the maximum stiffness of virtual contact that can be rendered to users. The analysis predicts that: (i) passive wave communications increase the maximum stiffness of the remote dynamic proxy coordination; (ii) the maximum contact and coordination stiffness are unaffected by fixed network delays; and (iii) the interacting users perceive smooth contact forces even for large network delays. Experiments in which two users probe each other with similar haptic interfaces validate the analytical results. Keywordsdirect user-to-user touch; distributed networked haptic systems; passive wave-domain communications; remote dynamic proxies;