A bilateral teleoperation experiment with Engineering Test Satellite 7 (ETS-VII) was conducted on November 22, 1999. Round-trip time for communication between the National Space Development Agency of Japan ground station and the ETS-VII was approximately seven seconds. We constructed a bilateral teleoperator that is stable, even under such a long time delay. Several experiments, such as slope-tracing task and peg-in-hole task, were carried out. Task performance was compared between the bilateral mode and the unilateral mode with force telemetry data visually displayed on a screen. All tasks were possible by bilateral control without any visual information. Experimental results showed that kinesthetic force feedback to the operator is helpful even under such a long time delay, and improves the performance of the task.

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.

A bilateral teleoperation experiment with ETS-VII was conducted on November 22, 1999. Round-trip time for communication between the NASDA ground station and ETS-VII was approximately six seconds. We constructed a bilateral teleoperator that is stable even under such a long time delay. Several experiments, such as slope tracing task and peg-in-hole task, were carried out. Experimental results showed that kinesthetic force feedback to the operator is helpful even under such long time delay and improves the performance of the task.

An experiment to teleoperate a robot arm on a satellite from an onground control station was conducted by an astronaut who has extensive on-orbit experience in operating the Space Shuttle's robotic arm. This experiment aimed to evaluate/compare a teleoperation system, which we developed, with the teleoperation system of the Space Shuttle Remote Manipulator System (SRMS). There was a time delay of about 6 seconds in the teleoperation control loop of the satellite-mounted robot. However, the teleoperation experiments were satisfactory conducted with helps of various operator assistance functions.

Tasks to be performed in space will increase in near future such as assembly of the space station, exploration of lunar and Mars surface, repair of failed satellites in orbit. Space robots which can be teleoperated from a ground control station are desired to conduct these tasks. National Space Development Agency of Japan (NASDA) is to launch an engineering test satellite named ETS-VII to conduct rendezvous docking and space robot technologies experiments for the above future missions. ETS-VII satellite has 6-DOF robot arm of about 2 m long which will be teleoperated from an on-ground control station in Japan. This paper describes the teleoperation system of the ETS-VII robot arm.

A macro-micro manipulator system has been proposed with the purpose of overcoming the difficulty to realize a trajectory tracking control of a flexible manipulator. In this paper, a trajectory tracking controller of macro-micro manipulator system is proposed which takes the dynamics of the system into consideration. This control law consists of a simple PD feedback law for the macro flexible manipulator and a dynamic trajectory tracking control law for the micro rigid manipulator. Experimental results show the effectiveness of the proposed scheme.>