In our previous research, we developed space robot teleoperation technology to achieve control from the ground of effective manual manipulations in orbit. To solve the communication time delay in the space robot teleoperation, we propose a mixed force and motion command-based space robot teleoperation system that is a model-based teleoperation. Moreover, we have also developed a compact 6-degree-of-freedom haptic interface as a master device. The important features of our teleoperation system are its robustness against modeling errors and its ability to realize the force exerted by the operator at the remote site. We introduce a new control method, which modified our model-based teleoperation system, to control the real robotic system Engineering Test Satellite VII manipulator. Surface-tracking and peg-in-hole tasks have been performed to confirm the effectiveness of our system. The experimental results obtained with our system including the haptic interface demonstrate its ability to perform these tasks in space without any major problems. We also evaluated different master device approaches for the model-based space teleoperation system. For this purpose, we used two methods, which are a master-slave (MS) approach and a force-joystick approach. Our results show that the MS approach is the best control method for contact tasks in which the directions of motion of the slave arm and of the operator's input force are different, as in the surface-tracking task.

In our previous works, we have proposed a mixed force and motion commands-based space robot teleoperation system and a compact 6-DOF haptic interface to achieve an effective manual teleoperation. Until now, the effectiveness of this system and the haptic interface has been confirmed by the experiments in our laboratory. The most important features of this teleoperation system are robustness against modeling errors and ability to realize the operator exerted force at a remote site. In this paper, elements of this system and the haptic interface have been employed to teleoperate the 6-DOF manipulator mounted on the Engineering Test Satellite VII (ETS-VII) which is a real space robotic system. Surface-tracking and peg-in-hole tasks with modeling errors have been executed in this experiment. The results show that our space robot teleoperation system including the haptic interface has been able to execute these tasks in real space environment without any big problems.

In our previous work, several system elements for space teleoperation were introduced: a Singularity Consistent (SC) teleoperation system, a mixed force and motion commands based space teleoperation system, and a 6-DOF haptic interface (Y. Tsumaki and M. Uchiyama, 1997; Y. Tsumaki et al., 1998). We introduce an advanced space teleoperation system which includes all the above elements. As a result, the system realizes safety against the singularities and excessive force, with good perception for the operator. In addition, to verify the effectiveness of this system, we conducted experiments through the Internet between DLR in Germany and Tohoku University in Japan in January 1999.