Stable and Transparent Time-Delayed Teleoperation by Direct Acceleration Waves

For time-delayed bilateral teleoperation systems, this paper presents a novel structure to considerably improve performance in terms of transparency and perception bandwidth, which are extremely low for passive systems, as well as force-position and velocity tracking on which delay control systems suffer both necessity for provision of identical initial conditions and drift problem. Performance improvement is carried out in three steps. The first step is the utilization of a four-channel wave-transmission structure that provides direct force and velocity feedbacks to each robot by asymmetric damping. Since the common dimension of wave variables is acceleration, the second step is the conversion of wave data into acceleration terms and the employment of acceleration control. The third step is the scaling of both the force- and position-based acceleration dimensions. Perception-bandwidth-limiting filters are used neither in wave space nor in control space. We showed the validity by experiments and superiority to previous systems by various comparative analyses.