Virtual repulsive force field guided coordination for multi-telerobot collaboration

The Intelligent Systems Laboratory (ISL) has been developing coordinated control technologies for multitelerobot collaboration, in a common environment remotely controlled from multiple operators physically at a distance from each other. We have built a test bed and conducted a series of experiments, where we learned more about how the transmission delay over the network deteriorates the performance of telerobots. Previously, to overcome the problems arising from the throughput of the network such as the operator's delayed visual perception, we have suggested several coordination approaches in the local operator site. Likewise, this paper discusses the use of virtual repulsive force field in the online predictive simulator to assist the operator to cope with the collision between telerobots in remote environments. In the test bed, the operators control their master robot to get remote telerobots to work cooperatively with the other telerobots in a task. Specifically, the operator detects a priori the possibility of collision in the predictive simulator that runs in near real-time and the use of virtual force field prevents the telerobots from coming into collision. We have demonstrated various tasks by two telerobots and two operators via an Ethernet local area network (LAN) subject to simulated communication delays and evaluated the validity of the virtual force field guided approach in multi-operator-multi-robot (MOMR) tele-collaboration.