### High-speed Catching Based on Inverse Motion Approach

## Summary

We had developed "High-speed Throwing Motion Based on Wave Propagation (throwing strategy)". On the other hand, there is a catching strategy to minimize the velocity difference between ball and manipulator at the moment of catching. This strategy is effective in terms of making impact smaller and avoiding flipping a ball because the velocity difference is small. However, with this strategy we can only catch a slower ball than the maximum velocity of the arm because we must move the arm at the same velocity as the ball. In other words, we must move the arm at high speed to catch a high-speed ball.

We consider that we can achieve catching a faster ball by applying the throwing strategy. Therefore, we propose catching strategy using the inverse motion of the throwing motion because catching and throwing move in opposite direction. Here we defined "Inverse motion" as the motion that played the original motion backwards. However, we can't generate catching motions simply, because the inverse motion is the motion that played the original motion backwards and the throwing strategy is calculated by optimal calculations. Therefore, we calculate several types of the inverse motion of throwing motion preliminarily and generate the catching motion by interpolating the inverse motions based on trajectory of the ball. We achieved catching a ball in planar motion.

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#### References

- K. Murakami, T. Senoo and M. Ishikawa: High-speed Catching Based on Inverse Motion Approach, 10th SICE System Integration Division Annual Conference(SI2009). (Tokyo, Japan, 2009. 12. 25)/Proceedings, pp.1363-1364.
- K. Murakami, T. Senoo and M. Ishikawa: Catching Based on Inverse Motion Approach With a Multi-Jointed Arm, The 28th Annual Conference of the Robotics Society of Japan. (Nagoya, Japan, 2010. 9. 22)/Proceedings, 1M23-5.
- K. Murakami, T. Senoo and M. Ishikawa: Real-Time Trajectory Planning with the Inverse Motion for High-speed Catcing, 2011 JSME Conference on Robotics and Mechatronics(ROBOMEC2011).(Okayama, Japan, 2011. 5. 28)/Proceedings, 2P2-03
- K. Murakami, T. Senoo and M. Ishikawa: High-speed Catching Based on Inverse Motion Approach, 2011 IEEE International Conference on Robotics and Biomimetics(ROBIO2011).(Phuket, 2011.12.9)/Proceedings, pp.1308-1313
- K. Murakami, T. Senoo and M. Ishikawa: Catching Motion Based on Inverse Motion Approach with High-speed Multifingered Hand, 12th SICE System Integration Division Annual Conference(SI2011). (Kyoto, Japan, 2011. 12. 24)/Proceedings, pp.1409-1411.
- K. Murakami, T. Senoo and M. Ishikawa: Catching Strategy Based on Time-Revering Approach, 17th Robotics Symposia, (Hagi, Yamaguchi, Japan, 2012. 3. 15)/Proceedings, pp.580-585