# Virtual Reality-Based Interface for Advanced Assisted Mobile Robot Teleoperation
## 4 Conclusions  
A virtual reality-based interface for advanced assisted teleoperation of mobile robots was developed in this work to assist human operators to conduct operations, such as human rescue, bomb deactivation, etc. For this purpose, virtual reality and sensor feedback were used to provide the user an immersive virtual experience when remotely teleoperating the robot system in order to properly perform the task.  
The main advantages of the proposal are twofold. Firstly, the proposed virtual environment is useful to provide a more natural manner to teleoperate these kind of robots, which improves the task performance. Secondly, the synergistic effect between the human, who provides flexibility to adapt to complex situations, and the robot, which is able to automatically avoid the obstacles in its environment, makes the proposed approach user friendly and allows the robot to deal with challenging situations, e.g., to escape from trap situations.  
Furthermore, the feasibility and effectiveness of the proposed virtual reality interface for advanced assisted teleoperation of mobile robots were shown through experimental results, using a differential-drive mobile robot, the Turtlebot3 Burger, equipped with a 360  
Figure 12: Results of the SUS questionnaire (mean and standard deviation).  
\begin{table}
\begin{tabular}{c l} \hline \hline SUS1 & I think that I would like to use this system frequently \\ \hline SUS2 & I found the system unnecessarily complex \\ \hline SUS3 & I thought the system was easy to use \\ \hline SUS4 & I think that I would need the support of a technical person to be able to use \\  & this system \\ \hline SUS5 & I found the various functions in this system were well integrated \\ \hline SUS6 & I thought there was too much inconsistency in this system \\ \hline SUS7 & I would imagine that most people would learn to use this system very quickly \\ \hline SUS8 & I found the system very cumbersome to use \\ \hline SUS9 & I felt very confident using the system \\ \hline SUS10 & I needed to learn a lot of things before I could get going with this system \\ \hline \hline \end{tabular}
\end{table}
Table 3: Questions of the SUS questionnaire [80].  
LiDAR sensor. Although in this work, only the robot odometry and LiDAR sensor were used, the information provided from other sensors, such as vision systems, could be easily added in order to include in the local environment (virtual world) more information from the remote environment (real world).  
In addition, several usability and presence questionnaires were carried out with users of different ages and backgrounds. The results showed that the proposed virtual reality based interface is intuitive, ergonomic and easy to use.  
This work assumed that the robot goes through a totally unknown environment. If there is previous knowledge of the environment, one possibility would be to improve the teleporting option by showing the \"allowed\" areas in a blue circle (such as the one shown in this work) and the \"not allowed\" areas with a red circle, thus constraining the user movements within the virtual world.  
Moreover, if the environment is totally or partially known, it would be interesting to introduce a trajectory planner, which in combination with the manual teleoperation carried out by the human, would lead to a semi-automatic teleoperation mode. In this mode, the planner would indicate the optimal trajectory to the human operator, who would be free to follow it or not depending on the situation.  
In this work, the well-known potential field-based navigation method was used for the high-level controller of the mobile robot. However, other controllers could be considered to improve the performance of the mobile robot navigation in different ways, e.g., sliding mode control approaches [81] or intelligent model-free control approaches [82] could be used.  
The authors declare no conflict of interest.