Enhanced stability of three-users multirate distributed haptic cooperation via coordination to average peer position

Abstract—Distributed networked haptic cooperation may be-come unstable when the number of interacting users increases because the effective coordination gain for the shared virtual object increases. The average position coordination strategy maintains the coordination gain of the shared virtual object constant regardless of the number of cooperating participants. Therefore, the average position strategy is expected to increase the stability region of networked haptic cooperation among multiple users. This paper confirms through analysis and experiments that AP coordination maintains the three-users haptic cooperation stable for larger coordination gains than traditional virtual coupling coordination. The stability analysis is performed in a multirate control framework. Multirate control is deployed to support high sampling rate of the peer force feedback loops in the presence of a low network update rate. The experiments report a one degree of freedom manipulation of a virtual cube by three cooperating users. Keywords-Networked haptic cooperation; distributed control; multirate control; coordination to averaged position. I