Coordinated rate control of multiple telerobot systems with time delay

In this paper, a collision-free coordinated rate control scheme was discussed for Multi-Operator-Multi-Robot (MOMR) teleoperation using a network with communication time delay. Over the past decades, problems and several noticeable results have been reported mainly in a Single-Operator-Single-Robot (SOSR) teleoperation system. Recently, collaboration tasks have rapidly emerged in many possible applications such as the plant maintenance, construction, and surgery, because multi-robot collaboration would have a significant advantage over a single robot in such cases. Thus, time-delayed control of multi-robot system are highly expected to play an important role in remote operations, too. However, the effect of time-delay would pose a more difficult problem to MOMR teleoperation systems and seriously affect their performance. In this work, first, the time-delay problems in remote collaboration through MOMR teleoperation were investigated. Then, the scaled rate control method was proposed to cope with the collision arising from the time-delay in MOMR teleoperation system. We scaled down the velocity of the slave end-effector when the possible collision was expected during the collaboration. To verify the validity of the proposed scheme, an experiment on planar block arrangement by two slave manipulators was performed based on simulation models.