Experimental results on the control of a robot bilateral teleoperation system with time varying delays

Abstract

Bilateral systems of teleoperation are useful in a wide range of tasks that can be dangerous or inaccessible for a human operator. However, when time varying delays appear in the communication channel, perfect transparency can no longer been sured. Instead, other control objectives may be pursued, such as the kinematic correspondence between the local and the remote robots. Furthermore, since most of the commercially available robots are not equipped with velocity sensors, to guarantee a certain level of transparency or kinematic correspondence the controller can not rely on velocity measurements. This article is focused on presenting the experimental results of a robust scheme to time delays for non-linear manipulators connected through a communication channel. The main advantages of the control scheme are: i) it is not necessary to know the dynamic parameters of the manipulators; ii) it is not necessary to impose restrictions in the behavior of the human operator and the remote surface; iii) an estimation of velocities is obtained through a second order linear filter; iv) a term that guarantee force tracking is added to the scheme as well. In order to show good performance, we report a set of experiments that have been carried out between different cities in Mexico using the Internet as a communication channel.

Keywords

• teleoperadores bilaterales
• diseño de observadores
• retardos variantes en el tiempo
• correspondencia cinemática retardada