# A Telepresence Wheelchair with 360-Degree Vision Using WebRTC
## 3 Results
### Experiment 3: Evaluation of Remote Control Telepresence Wheelchair  
The purpose of the experiment was to assess the improvement of performance and to further demonstrate the effectiveness of the remote controlling function of our design. The tests were carried out by remote controlling the wheelchair in three locations in both indoor and outdoor environments. Ten experiments were conducted in each location. The average time spent on each test was two hours. The remote users were in a separate room where they could not see the paths and the targets, and they could only see them while driving the wheelchair through the telepresence function with 360-degree vision. Firstly, the experiments were conducted in an indoor environment at the Centre for Health Technologies, where some free spaces were available. The tests were performed on the balcony where there is a wireless signal, as shown in Figure 14. This environment was considered to be completely unknown to the remote user in each operation time. The remote user was far away from the wheelchair and was required to control the wheelchair to reach specified targets. Figure 14 shows the environment and a trajectory produced by the wheelchair in the experiments. Starting from point A, the remote user controlled the wheelchair to move towards points B, C, D, and E, respectively, via the control of the remote user via a web browser. The wheelchair created a trajectory marked by the red dotted line. This trajectory is the result of the user commands during the navigation process. The results show that the remote user was easily able to move forward and control the wheelchair straight ahead. Secondly, the experiments were conducted in our laboratory's room. The test area is about 30 square meters. Objects have been placed in the test room to recreate a real home environment. The driving path is more challenging than that in the previous experiment. A path in a figure-eight curve was drawn on the floor using a bright white dashed line, as shown in Figure 15a,b. It was marked to help the remote user to perform the task and to avoid obstacles in the room. The visual results of this experiment are illustrated in Figure 16. In this experiment, the remote user was asked to drive the wheelchair following the route, which was drawn on the floor. During experiments, all trails in the testing were also video recorded, and the paths were traced and then used for evaluations. Figure 14: System performance test (**a**) and trajectory of the wheelchair when the remote user controlled the wheelchair with straight-ahead directions (**b**). Figure 15: The full field of view obtained at the remote user (**a**) and test path setup with the figure-eight curve (**b**). and other recent approaches based on traditional platforms [23]. The results reveal the promise and potential of WebRTC for such a real-time telepresence wheelchair system. From an implementation point of view, real-time video streaming implementation over wireless networks faces various problems due to both the nature of wireless radio channels and the stringent delivery requirements of media traffic. One of the biggest issues are the unpredictable behaviors of wireless channels due to the fluctuation of the wireless signals and wireless channel conditions. Therefore, one of the primary objectives of video streaming over the wireless network is to deal with the fluctuation of an unknown and dynamic wireless signal. It is important to match the video bitrate to that which the channel can support to improve the quality of video transmission in a wireless network. Thus, it is highly desired that the video streaming scheme can adapt the bit rate according to network conditions. This study has considered WebRTC that are implemented at the sender and the receiver. The initial results of the first experiment (telepresence wheelchair based on WebRTC) show that the connection time of WebRTC is faster with less latency than the Skype platform.