# Remote Control Device to Drive the Arm Gestures of an Assistant Humanoid Robot
## 6 Discussion and Conclusions
The results show that the APR-02 mobile robot required from 120 to 540 ms to replicate the position of the arms of the remote control device, which represents an average structural delay of 274 ms. The evaluation of this structural delay has also shown that the use of a target sampling time of 20 ms in the remote controller device does not generate discontinuities or data loss during the replication of the gestures. A third experiment was conducted to measure the total telecontrol delay, which cumulatively includes the communication delay required to send the target information from the remote control device and to receive it on the robot plus the structural delay required by the robot to replicate the joint positions received. The total telecontrol delay has been estimated by comparing the gesture established in the remote control device and the gesture of the humanoid robot. Some of the gestures assessed include upwards, downwards, lateral and circular movements, waves and claps. This experiment has shown that the humanoid robot is able to replicate any target gesture successfully. The telecontrol delay measured while performing these gestures was found in a range from 340 ms to 900 ms with an average value of 549 ms. Although time delay and data missing during networked communication are inevitable [20], the results showed no jumps, discontinuities or data loss during the development of all the gesture experiments performed in this work. At this point, it should be noted that the communication delay in a remote telecontrol application depends on the quality and performance of the communication network [67; 77]; for example, they can be significantly enhanced by using a 5G device-to-device communication [70; 71]. In this work, the teleoperator performing the gestures tried to perform all movements using a normal (not too fast and not too slow) human speed. However, the highest telecontrol delays have been achieved in the cases in which the operator moved the arms upwards and circularly (inwards), which were the fastest gestures assessed. These results agree with the imitation experiments conducted by [PERSON] et al. [48], who concluded that gesture error is correlated with the velocity of the gesture. In any case, similarly to the results obtained by [PERSON] et al. [48] and [PERSON] et al. [49] controlling an NAO robot, the communication delay did not compromise the dynamic visual perception of the remote operator controlling the humanoid robot and the user perception while interacting with the robot. The development of the experiments has validated the importance of the gamepads included in the remote control device as they provide direct access to some common robot functionalities without releasing the hands from the controller. These results agree with [PERSON] et al. [58], who stated that the physical control of input devices plays an important role in the link between the robot and the remote operator. As a final conclusion, the direct manipulation of the passive arms of the remote control device provides the APR-02 humanoid robot with enhanced non-verbal and pointing communication capabilities during human interaction or assistance.