Comparison of power- and wave-based control of remote dynamic proxies for networked haptic cooperation

This paper investigates through experiments the performance of two recent control architectures for networked haptic cooperation. The two architectures can render direct haptic interaction between networked users in addition to cooperative manipulation of virtual objects. This is because both architectures employ remote dynamic proxies to represent users at their networked peer sites. The remote dynamic proxies have second order dynamics and are controlled by the distant user whom they represent via virtual coupling (i.e., power-based) control or via wave-based control. The remote dynamic proxies render smooth motion of their respective user in the presence of update discontinuities caused by limited network transmission rates and by network delays. The experimental comparison investigates the performance of cooperative manipulation and of direct user-to-user contact for various constant network delays. The results illustrate that: (1) both power-based and wave-based control of remote dynamic proxies can maintain high position coherency between the distributed copies of the shared virtual object; (2) wave-based control of remote dynamic proxies renders the inertia of the shared virtual object and of the remote dynamic proxies more realistically than virtual coupling control; and (3) wave-based control of remote dynamic proxies maintains the networked haptic cooperation stable for longer constant network delays.