Classification of Prism Object Shapes Utilizing Tactile Spatiotemporal Differential Information Obtained from Grasping by Single-Finger Robot Hand with Soft Tactile Sensor Array
Kenshi Watanabe*, Kenichi Ohkubo*, Sumiaki Ichikawa**,
and Fumio Hara*
*Department of Mechanical Engineering Tokyo University of Science, 1-3 Kagurazaka, Shinjyuku-ku, Tokyo 162-8601, Japan
**Faculty of Systems Engineering, Tokyo University of Science, 5000-1 Toyohira, Chino-shi, Nagano 391-0292, Japan
Our proposal involves classifying cylindrical objects by using soft tactile sensor arrays on a single five-link robotic finger. The front of each link is covered with semicircular silicone rubber with 235 small on-off switches. On-off data from switches obtained when an object is grasped is converted to a spatiotemporal matrix. Eight cells around the contact switch are useful in extracting local spatiotemporal contact physics, so the frequency of the 8-Cell patterns composed of binary data around the switch contacted is obtained for each object and used to form a contact-feature vector. This vector is obtained 10 times of experimental trial, corresponding to each object. Vectors are classified by the Mahalanobis distance for 12 objects – cylinders and regular polygonal prisms – resulting in 14 types of grasping (14 classes). Using 6 dimensional feature vectors, over 95% classification accuracy is obtained for 7 classes derived from 5 objects having one or two types of stable grasping.
and Fumio Hara, “Classification of Prism Object Shapes Utilizing Tactile Spatiotemporal Differential Information Obtained from Grasping by Single-Finger Robot Hand with Soft Tactile Sensor Array,” J. Robot. Mechatron., Vol.19, No.1, pp. 85-96, 2007.
-  G. Kinoshita, “Feature Extraction of Grasped Object’s Shape by the Artificial Hand with Tactile Sensors,” Transactions of the Society of Instrument and Control Engineers, Vol.14, No.1, pp. 90-96, 1978.
-  T. Okada, “Patten Recognition of an Object by Grasping, Bulletin of the Electrotechnical Laboratory,” Vol.40, No.9, pp. 733-747, 1976.
-  K. Kudo, S. Sato, and M. Takata, “Pattern Recognition of an Object by Artificial Fingers with Sense Organs,” Transactions of the Society of Instrument and Control Engineers, Vol.10, No.3, pp. 378-384, 1974.
-  M. H. Lee and H. R. Nicholls, “Tactile sensing for mechatronics – a state of the art survey,” Mechatronics, Vol.9, pp. 1-31, 1999.
-  H. Shinoda, “Tactile Sensing for Dexterous Hand,” Journal of the Robotics Society of Japan, Vol.18, No.6, pp. 767-771, 2000.
-  Y. Yamada, “References of References in Robotic Touch Sensing and Human Touch Sensation,” Journal of the Robotics Society of Japan, Vol.16, No.7, pp. 893-896, 1998.
-  Y. Tada, K. Hosoda, Y. Yamasaki, and M. Asada, “Sensing Texture of Surface by Anthropomorphic Soft Fingertips with Multi-Modal Sensors,” Proceeding of the 2003 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 31-35, 2003.
-  H. Shinoda, K. Matsumoto, and S. Ando, “Acoustic Resonant Tensor Cell for Tactile Sensing,” Proceedings of IEEE Int. Conf. on Robotics and Automation, pp. 3087-3092, 1997.
-  T. Miyasita, M. Inoue, K. Suganuma, and H. Ishiguro, “Development of Artificial Skin Sensor Surrounded Piezoelectric Device inside Silicone Rubber,” Leading Edge of Super Five Senses Sensors, NTS, pp. 357-369, 2005.
-  T. Mukai, “Soft Areal Tactile Sensors with Embedded Semiconductor Pressure Sensors in a Structured Elastic Body,” Proc. of IEEE Sensors 2004, pp. 1518-1521, 2004.
-  T. Suehiro, “Robot Arm that Has Whole Body Tactile Sensors,” Leading Edge of Super Five Senses Sensors, NTS, pp. 273-286, 2005.
-  Y. Iwamura, “Structure and Characteristic of Human Tactile Receptors,” Journal of the Robotics Society of Japan, Vol.2, No.5, pp. 438-444, 1984 (in Japanese).
-  T. Maeno, “Structure and Function of Finger Pad and Tactile Receptors,” Journal of the Robotics Society of Japan, Vol.18, No.6, pp. 772-775, 2000.
-  K.Watanabe, S. Ichikawa, and F. Hara, “A multi-link robotic fingertype soft touch-sensor system,” Proc. of IEEE Sensors 2004, pp. 1530-1533, 2004.
-  K. Watanabe, K. Ohkubo, S. Ichikawa, and F. Hara, “Study on simultaneous classification of object properties by using soft tactile sensor array system utilizing local spatial-temporal information of contact,” Transaction of The Japan Society of Mechanical Engineers Series C, Vol.72, No.721, pp. 2964-2971, 2006.
-  H. Aoki, “Design and Making of Analogue Circuit,” pp. 216-217, CQ Publishing, 1989 (in Japanese).
-  N. Ootsu, T. Kurita, and I. Sekita, “Pattern Recognition – Theory and Application,” pp. 165-181, Asakura-shoten, 1996 (in Japanese).
-  K. Watanabe, K. Ohkubo, S. Ichikawa, and F. Hara, “Tactile Information Processing by Soft Tactile Sensor Array System Utilizing Local Spatial-Temporal Information of Contact –Shape Classification of Prism Objects with Contact Strength–,” Robomec 2006 in Waseda, CD-ROM, 2P2-B10, 2006.
-  K.Watanabe, “Study of Recognition Characteristics of Object Property by Soft Tactile Sensor,” Department of Mechanical Engineering, Tokyo University of Science 2002 year Master’s Thesis, pp. 11-12, 2003.
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