Volume 22 Issue 5 - Publication Date: 1 May 2003
Engineering Test Satellite VII Flight Experiments For Space Robot Dynamics and Control: Theories on Laboratory Test Beds Ten Years Ago, Now in Orbit
Kazuya Yoshida Department of Aeronautics and Space Engineering, Tohoku University, Sendai, 980-8579, Japan
The Engineering Test Satellite VII (ETS-VII), an unmanned spacecraft equipped with a 2-m long, six-degree-of-freedom manipulator arm, was developed and launched by the National Space Development Agency of Japan (NASDA). ETS-VII has successfully carried out a variety of on-board experiments with its manipulator arm, and these key technologies are essential for an orbital free-flying robot. These results will provide a solid basis for future satellite servicing missions. This paper highlights manipulator control utilizing the concepts of the generalized Jacobian matrix and the reaction nullspace. These concepts have been proposed and discussed for the past ten years using laboratory test beds, and their practical application has now been demonstrated in orbit.
Multimedia Key
= Video = Data = Code = Image
Example One: Target capture experiments carried out with a horizontal free-floating test bed, EFFORTS (1987, at Tokyo Institute of Technology). The first is the experiment to reach a static target which corresponds to Fig. 2 (b). The second is the experiment to chase a moving target with visual servo using a ceiling camera. (15.0 MB)
Example Two: Demonstration of the conventional manipulation and the reactionless manipulation using a test bed for flexible-base manipulator, TREP (1996, Tohoku University). Experiment 1 corresponds to Fig. 4 (a). Experiment 2 corresponds to Fig, 4 (b). (5.4 MB)
Example Three: Operation of the ETS-VII. Two different views of on-board cameras, a ground track of the orbit, and real-time simulation (1999, NASDA). The top right image corresponds to Fig. 6. (13.0 MB)
Example Four: Simulation of target capture operation by a combination of the RNS-based reactionless manipulation for the initial approach and the GJM-based inertial manipulation for the final approach. The motion corresponds to Fig. 14. (4.8 MB)
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