1. a Graduate School of Computers and Systems Engineering, Tokyo Denki University, Hatoyama-cho Ishizaka, Hiki-gun, Saitama 350-0394, Japan
2. b Department of Robotics and Mechatronics, Tokyo Denki University, 2-2 Kanda-Nishiki-cho, Chiyoda-ku, Tokyo 101-8457, Japan
3. c Department of Robotics and Mechatronics, Tokyo Denki University, 2-2 Kanda-Nishiki-cho, Chiyoda-ku, Tokyo 101-8457, Japan
4. d HOSHINO ING Corporation, 652-1 Niijima-cho, Oota-shi, Gunma 373-0819, Japan