1. Department of Robotics, Faculty of Engineering, Kindai University, Higashi-Hiroshima, Japan
2. Mechatronics Major, Faculty of Systems Engineering, Wakayama University, Wakayama, Japan
3. Department of Electronics and Informatics, Faculty of Science and Technology, Ryukoku University, Otsu, Japan
4. Graduate School of Science and Engineering, Saitama University, Saitama, Japan
5. Department of Mechanical Engineering, Materials Science, and Ocean Engineering, College of Engineering Science, Yokohama National University, Yokohama, Japan
6. Faculty of Engineering, Information and Systems, University of Tsukuba, Tsukuba, Japan
7. National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
8. Department of Robotics, Faculty of Robotics and Design, Osaka Institute of Technology, Osaka, Japan
9. Department of Mechanical Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan