# Augmented Reality-Based Interface for Bimanual Robot Teleoperation
## 4 Results
Figure 10: Second experiment: frames of the video showing the performance of the 2D boundary and the STR reference hologram. See the video at [[https://media.upv.es/player/?id=9504e6f0-8a61-11](https://media.upv.es/player/?id=9504e6f0-8a61-11) ec-b7c7-7d27 da2c5d5]([https://media.upv.es/player/?id=9504e6f0-8a61-11](https://media.upv.es/player/?id=9504e6f0-8a61-11) ec-b7c7-7d27 da2c5d5) (accessed on 26 April 2022) [82]. (**a**) Video: 0 m 31 s. (**b**) Video: 0 m 41 s. (**c**) Video: 1 m 5 s. (**d**) Video: 1 m 46 s.  
Figure 12 shows the position followed by the STR tool on the workpiece surface, which is due to the STR teleoperation, together with the reference values provided by the user. In particular, it can be appreciated that the trajectory described by the STR tool corresponds closely to the user reference values, except obviously when the 2D boundary constraint is active; see the bottom graph in Figure 12. In fact, the maximum deviation of the actual STR position values compared to the user reference values, when the 2D boundary constraint was not active, was around 3.2 cm, with a standard deviation of around 0.8 cm; see Table 2. Note that these teleoperation error values include all the potential sources of error: communication delays, high-level and low-level robot control, the accuracy of the workpiece location, teleoperation system, etc. Therefore, it can be concluded that the accuracy of the proposed AR-based teleoperation of the STR is sufficient for the task at hand. Figure 13 shows several frames of the _third experiment_, which shows the performance of the 3D boundary and the WR reference hologram; see the video at [[https://media.upv.es/player/?id=17d88200-8f0b-11](https://media.upv.es/player/?id=17d88200-8f0b-11) ec-be22-d786 eca82090]([https://media.upv.es/player/?id=17d88200-8f0b-11](https://media.upv.es/player/?id=17d88200-8f0b-11) ec-be22-d786 eca82090) (accessed on 26 April 2022) [83]. Figure 13a shows how the user is commanding the WR and, when the WR end-effector approaches the 3D boundary, the boundary region closest to the WR end-effector is shown in blue and the warning sound is activated; see Figure 13b-d. Note that, when the user reference exceeds the 3D boundary, the WR end-effector is automatically kept within the allowed region. More details about this aspect can be further analyzed in Figure 14, \begin{table}
\begin{tabular}{c c c} \hline \hline  & \multicolumn{2}{c}{**Position (cm)**} \\  & \(\mathbf{x}\) & \(\mathbf{y}\) \\ \hline Maximum deviation & 1.8 & 3.2 \\ \hline Standard deviation & 0.5 & 0.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Teleoperation errors for the 2D position \(\overline{\mathbf{p}}_{s}\) of the STR tool on the workpiece surface. Figure 12: Performance of the STR position teleoperation for the second experiment. First two graphs: user position references in thin red line, actual position values of the STR tool on the workpiece surface (coordinates relative to the surface) in thick blue line, and position limits given by the 2D boundary constraint in dashed lines. Bottom graph: activation of the 2D boundary constraint for the position of the STR tool on the workpiece surface. which shows the allowed 3D region, the trajectory followed by the user reference, and the trajectory followed by the WR end-effector. Figures 15 and 16 show the position and orientation, respectively, followed by the workpiece, which are due to the WR teleoperation, together with the reference values provided by the user.