Shunichi Kawabata

Multioperator teleoperation of multirobot systems with time delay: part I--aids for collision-free control

In this paper, various coordinated control schemes are explored in Multioperatormultirobot (MOMR) teleoperation through a communication network with time delay. Over the past decades, problems and several notable results have been reported mainly in the Single-OperatorSingle-Robot (SOSR) teleoperation system. Recently, the need for cooperation has rapidly emerged in many possible applications such as plant maintenance, construction, and surgery, because multirobot cooperation would have a significant advantage over a single robot in such cases. Thus, there is a growing interest in the control of multirobot systems in remote teleoperation, too. However, the time delay over the network would pose a more difficult problem to MOMR teleoperation systems and seriously affect their performance. In this work, our recent efforts devoted to the coordinated control of the MOMR teleoperation is described. First, we build a virtual experimental test bed to investigate the cooperation between two telerobots in remote environments. Then, different coordinated control aids are proposed to cope with collisions arising from delayed visual feedback from the remote location. To verify the validity of the proposed schemes, we perform extensive simulations of various planar rearrangement tasks employing local and remote graphics simulators over an ethernet LAN subject to a simulated communication delay.

Remote collaboration through time delay in multiple teleoperation

In this paper, remote robot collaboration using a network with communication time delay is discussed in multi-operator-multi-robot (MOMR) teleoperation. Recently, collaboration tasks have rapidly emerged in many possible applications such as plant maintenance, construction, and surgery, because multi-robot collaboration would have a significant advantage over a single robot in such cases. Problems and several noticeable results have been reported in a single-operator-single-robot (SOSR) teleoperation system. However, the effect of time-delay would pose a more difficult problem to the MOMR teleoperation systems and seriously affect their performance. In this work, first, some of the constraints on performance in MOMR teleoperation applications are examined. Then, the time-delay effects on tele-collaboration are investigated through several experimental studies. Finally, a method to cope with the time-delay in MOMR teleoperation systems is proposed exploiting the virtual thickness modification scheme.