Analysis and Planning of Graspless Manipulation
(Prof. T. ARAI and Y. MAEDA)

Planned Tumbling Operation by Two Robot Fingers (MPEG-1 Movie)
Planned Tumbling Operation in Another Environment (MPEG-1 Movie)

Most of researches on robot motion planning deal with geometry-based planning, such as collision avoidance. In manipulation planning, however, we also have to consider mechanics. Especially in planning of graspless manipulation (Fig. 1), because of the unilateral nature of contact forces, a manipulator may be able to push an object but may not be able to pull it. The irreversibility of manipulation caused by mechanics makes planning more difficult.

We are trying to develop an algorithm to plan general graspless manipulation by robot fingers, and a theory of mechanical analysis required for the manipulation planning. We conducted mechanical analysis on manipulation stability and internal force in graspless manipulation. Based on these results, we solved planning problems of two-finger graspless manipulation. In consideration of the stability of the manipulation, motions of the fingers including regrasping were obtained as the optimal solution (Fig. 3).

Keywords: Manipulation Planning, Graspless Manipulation

References

Yusuke MAEDA and Tamio ARAI: “A Quantitative Stability Measure for Graspless Manipulation,” Proc. of 2002 IEEE Int. Conf. on Robotics and Automation, 2002 (to appear).

Yusuke MAEDA, Hirokazu KIJIMOTO, Yasumichi AIYAMA and Tamio ARAI: “Planning of Graspless Manipulation by Multiple Robot Fingers,” Proc. of 2001 IEEE Int. Conf. on Robotics and Automation, pp. 2474~2479, 2001.

Fig. 1 Graspless Manipulation Fig. 2 Planned Sliding Operation

Fig. 3 Planned Tumbling Operation with Regrasping